Ground and positive on pin 5 no clamp I think my meter was sensing ac from somewhere.

That is the wrong way to connect a current meter!:no:
Current is measured in series between the source and the load.
https://www.allaboutcircuits.com/textbook/experiments/chpt-2/ammeter-usage/
Your meter as well as the circuit could be damaged by such mis-use.
jr

That is the wrong way to connect a current meter!:no:
Current is measured in series between the source and the load.
https://www.allaboutcircuits.com/textbook/experiments/chpt-2/ammeter-usage/

jr

I know how to measure current I wasn’t measuring the current just the pin5 -45 to get the hv right.

I know how to measure current I wasn’t measuring the current just the pin5 -45 to get the hv right.

So you weren’t trying to measure current?

But your meter did this: “with the meter on number 5 of the hot my meter is showing 1.3 amps on the ac scale” ? :scratch2:
Confusing!

jr

My dvm I think picked up stray ac or ripple other stuff I had worked on this has happened even when it’s on dc if it picks up any ac it will display it on the top ac scale dc is on the bottom.

That is not how horizontal is adjusted on the set, in fact -45v is not an adjustment at all, but as I indicated, an voltage that shows that the oscillator is running and does not have to be exact, the frequency, timing and waveform there is what matters, and this is set by horz hold and hoz afc.

The ONLY measurements in the area are at the cathode of the HOT, and you do not have the meters to do this, you would need 2 meters that can measure current up to ½ amp, and do both tubes at once, cutting pin 2 from ground and putting a .47 uf cap from pin 2 to ground on both, and then measuring the current across that cap 120ma, both, but since this set does not seem to have a horizontal efficiency coil to adjust, this is not needed on this set.

What ever mistake you did in this, you most likely cremated your damper tube, and it will need to be replaced, it is rather weak and easy to damage, much more easy to hurt than the outputs.

So are you saying that with the hot red plating cooks the damper tube. So if 770 boost is gone then the damper is gone.

Certainly possible. I have a Silvertone CTC-15 clone that would short it's damper and completely loose HV if the horizontal frequency went too far off...It blew at least 2 good tubes when I was working on it. That was the first color set I restored to working and it sat a few months with dead HV because until I borrowed the damper for another set I and discovered it had failed I didn't retest it because it tested good before I lost HV.
That same set later had a weak damper that would test great unless you held the test button down for like 30+ seconds to get it to slump. That weakness caused unusably low HV.
Some problems are spooky in that the failed component WON'T test bad unless subjected to conditions more extreme than the normal use case of the test equipment.

Well back on track I made the couplet and found out where ac was riding on dc a defective power supply cap no more ac.

Hi!

A few observations....
1. When the Horiz Output tube in Timmy's set gets red plates, it's most likely due to a
poor horiz drive to G1, from improperly working Horiz Osc. Remember the damper
rectifies the collapsing coil field and makes the current available for use in other circuits.
It may be a good idea to replace it anyway since it does a lot of work.....

2. Timmy states that he adjusts the -45V to the G1's of the Horiz Output Tubes. He does
this with the Horiz. Hold control. By adjusting the frequency the resulting bias on
the G1's of the Horiz Output tubes moves closer to normal. Is it a good thing? Who
knows. - but it should keep the output circuit safe. Best idea would be that when
he feeds a signal to the tv and it gets a picture that locks, after that leave it alone.

3. Yamama suggested that once the tv gets a picture and the HV is normal, PS Voltages
are normal, that Timmy leave it alone for hours and see how long it runs like that. -
I Like that idea a lot! You really need to determine what causes the two states that
this tv operates at, A) Semi-Working, and B) Low HV and Red Plate HV Output tubes...
What causes these 2 states? Is it taking the chassis out? Putting it in?
4. AGC, a normal tv will work without HV fluctuating with an overloaded signal, and
with no signal at all it gets snow, and in both conditions no glowing plates on the
horiz output tubes.....

One thing Timmy needs to do is measure the AGC line voltage when the tv is working
and when it's in its Overheating tube state and see if there is a difference. If so, then
you need to set up a battery that can force that line between the 2 levels and see
if the AGC is the ultimate cause of this TV taking 34 pages to track down this problem.

Could the AGC be causing IF circuit tubes to be drawing too much current? If you are
going to order a new damper tube, then order a Voltmeter with 10A Current scale
too, and get one that is NOT Auto-range, get one that you have to turn the dial to
read 10A, 2A, etc. I'll say it again with a 10A Scale, the resistor inside the meter
is actually a piece of wire with almost 0 ohms, and you will have almost 0 resistance
added to the circuit when you measure 500ma, or 1/2 Amps.


.

Not sure where we are now but.......
To measure H Out current you need to open the cathode pin from GND
and put a ampmeter in series with it. Depending on the meter you should
decouple the cathode with a cap to smooth it out. It goes in // with the
meter.
SAMS has instructions on value of cap & procedure.
Adjusting the H. osc ( hold) will effect the G-1 negative voltage.
Keep in mind the whole thing by design needs to be in resonance
to be happy. If the G-1 is in spec you are good till that point.
A freq counter or scope can show you if its at 15,750.

AGC as a rule goes to the RF amp & IF # 1 & 2.
SAMS will show AGC voltages either with or without a strong signal
or both ways. AGC problems are VERY rare, I cant really remember
many in 40 yrs & tens of thousands of sets.

73 Zeno:smoke:
LFOD !

Not sure where we are now but.......
To measure H Out current you need to open the cathode pin from GND
and put a ampmeter in series with it. Depending on the meter you should
decouple the cathode with a cap to smooth it out. It goes in // with the
meter.
SAMS has instructions on value of cap & procedure.
Adjusting the H. osc ( hold) will effect the G-1 negative voltage.
Keep in mind the whole thing by design needs to be in resonance
to be happy. If the G-1 is in spec you are good till that point.
A freq counter or scope can show you if its at 15,750.

AGC as a rule goes to the RF amp & IF # 1 & 2.
SAMS will show AGC voltages either with or without a strong signal
or both ways. AGC problems are VERY rare, I cant really remember
many in 40 yrs & tens of thousands of sets.

73 Zeno:smoke:
LFOD !


As mentioned above, this set does not have a horizontal efficiency/linearity coil to adjust, so where the cathode current can be measured, there is no way to adjust it on this.

and yes AGC problems are rare, they do happen, bit in this case, it's more likely the IF alignment is messed up.

Tomorrow I’m going to check resistances on the 6hs8 according to sams. when I had this running the agc control on the rear turning both ways made no difference at all but the noise gate did I do get video but it is distorted but can see images so since making k1 will see what this does. There is a .4 v rf source to agc if that’s missing from the tuner I don’t know what the consequence is if that’s not there.

Checked resistances on 6hs8 they are all wrong even with the couplet I made up tried it anyway and it seemed to make it worse. I don’t know if the couplet all together would have to be potted I did incapsulated it in heavy heat shrink.

Checked resistances on 6hs8 they are all wrong even with the couplet I made up tried it anyway and it seemed to make it worse. I don’t know if the couplet all together would have to be potted I did incapsulated it in heavy heat shrink.

How far off were the resistances? Perhaps you could list the measurements by pin number, so we might be able to figure out what’s going on here.

I don’t think that the potting is important.

jr

My mistake I had to measure from x2 not x1 and it turns out they are all good. But the voltages are not right at all 6hs8 pins 6-145v 114 7-200 119 3-2.5 8.3 8-230 143 9-140 31 2- 275 1-190

My mistake I had to measure from x2 not x1 and it turns out they are all good. But the voltages are not right at all 6hs8 pins 6-145v 114 7-200 119 3-2.5 8.3 8-230 143 9-140 31 2- 275 1-190

Am I reading this right: “pin 9 140 volts expected, 31 volts measured” ?

jr

Yup

What is the input impedance of your dmm? Most dmms are 10 megohms, but some are only 1 megohm. SAMS specifies use of a VTVM (11 megohms) but a 10 megohm is usually good enough!

jr

What is the input impedance of your dmm? Most dmms are 10 megohms, but some are only 1 megohm. SAMS specifies use of a VTVM (11 megohms) but a 10 megohm is usually good enough!

jr

It's very doubtful that his meter is 10m, because he has an electrician's (clamp) meter, and not a full function DVM, this has been brought up several times before by quite a few, including myself that he invest in a better one that has a dedicated 10a scale, and was made for the electronics field rather than an electrician, because it is very likely it's giving inaccurate readings in some cases.

He has this.
http://www.instrumart.com/assets/uei-g2-phoenix-manual.pdf


Again, a better meter is suggested before believing any voltage readings, one that is known to be 10m, as the one on hand may be loading the circuit down.

Is it possible for a video detect diode to check good but be bad from leakage ? Has anyone ever seen this

It's very doubtful that his meter is 10m, because he has an electrician's (clamp) meter, and not a full function DVM, this has been brought up several times before by quite a few, including myself that he invest in a better one that has a dedicated 10a scale, and was made for the electronics field rather than an electrician, because it is very likely it's giving inaccurate readings in some cases.

He has this.
http://www.instrumart.com/assets/uei-g2-phoenix-manual.pdf


Again, a better meter is suggested before believing any voltage readings, one that is known to be 10m, as the one on hand may be loading the circuit down.

While not necessarily “better “ from a quality standpoint, this inexpensive dmm would be more suited to the task at hand.

https://www.amazon.com/gp/product/B00KHP6EIK/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

10 megohm input impedance (I have measured mine).
10 amp DC range.
No auto range (no confusion).
Inexpensive @ $12.50 (no tears if you break it).

not affiliated,
jr

While not necessarily “better “ from a quality standpoint, this inexpensive dmm would be more suited to the task at hand.

https://www.amazon.com/gp/product/B00KHP6EIK/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

10 megohm input impedance (I have measured mine).
10 amp DC range.
No auto range (no confusion).
Inexpensive @ $12.50 (no tears if you break it).

not affiliated,
jr

I have that exact one! :D

plus 2 other "disposable" types of the same price range.:yes:

Sounds like you guys won’t be happy until I buy a cheapy dvm or something from the early 60s. This dvm repaired many tvs. And the cap checker is priceless. I used to use a fluke 77 series and this I use now is better then that.

Sounds like you guys won’t be happy until I buy a cheapy dvm or something from the early 60s. This dvm repaired many tvs. And the cap checker is priceless. I used to use a fluke 77 series and this I use now is better then that.

funny you mention the fluke 77 series .

http://suzaku.live-evil.org/1004221812.jpg

what I and many other are saying is that the clamp meter you have is not 10m impedance, and that is quite important when it comes to tube stuff, there is a 90% chance that your voltage measurements are being skewed because of this.

$12.50 is a good investment to double check that you are being told correct voltage info with a meter KNOWN to be 10m, that both I and jr_tech have used, and I can say for a fact it gives readings on par with the Fluke.

Maybe this helps about this dvm

Maybe this helps about this dvm

but it does not say 10m impedance.
that is the important difference here, and why it can give faulty readings for some tube measurements.

https://xdevs.com/doc/Fluke/FLUKE%2077%2C%2075%2C%2073%2C%2070%2C%2023%2C%2021 %20Series%20II%20Service.pdf

note page 12 of this manual above.

input impedance
this is critical.

The link for Amazon I can’t get it says there’s a problem can you send they link again maybe it will work

Or the model number and I can look it up in Amazon

or the model number and i can look it up in amazon

msr-r500 MSR-A600 i have both

Msr - r500 is the one that is 10m impedance because it don’t say or show that I can find

jr_tech also has it, and he did the input impedance test on it, and it was 10m.

it a rather complicated thing to do with a voltage source and a 2nd DVM.

most DVMs of this type are, but most clamp meters are 1m.

So the msr- r500 is the one to grab

I guess that would explain why when I touch the probe I see a little tiny spark.

I guess that would explain why when I touch the probe I see a little tiny spark.

It's almost like adding an extra resistor to ground.

Well I don’t know how much this meter was affecting the voltage outcome a guess maybe 10-12 volts lower then what it is normally.

Ever since I accidentally let the hot red plate for like 40 seconds this is what I’m left with. Does this look like a bad damper. I am going to try a damper but I have both boost voltages so what’s this it looks like a bar generator but it’s not. Stumped again.

Already tried 2 new horizontal output tubes of course no change. One thing after another. So I need to find out what gives up when these tubes red plate to long.

A weak damper can cause low HV & insufficient horizontal width, but can also be a symptom of the horizontal osc being at the wrong freq, or a damaged HOT.

A new damper is a rather low cost first step in working out the problem.

A weak damper can cause low HV & insufficient horizontal width, but can also be a symptom of the horizontal osc being at the wrong freq, or a damaged HOT.

A new damper is a rather low cost first step in working out the problem.

So if the frequency is low then that’s why the bars are there and are you referring to hot as tube or flyback. I have 2 new dampers coming tomorrow.

HOT = horizontal output tube FBT = flyback transformer.

Wait till you get the new damper, then once again do the setup for direct video input at test point B, and then adjust horizontal hold to try to get lock, once you get lock, there should be no need to adjust it again.

Well I don’t know how much this meter was affecting the voltage outcome a guess maybe 10-12 volts lower then what it is normally.

Not necessarily, it depends on the circuit being tested. For example, the pin 9 measurement (31 volts measured, 140 volts expected): pin 9 is connected to the 190 volt supply through a 3.3 megohm resistor in series with a 470k resistor for a total of 3.77 megohms! A 1 megohm meter would be a considerable load, dropping the voltage about 150 volts! :thumbsdn:
Lower impedance circuits (such as power supplies) would be hardly affected at all by the load of a 1 megohm meter.

jr

Well there is a difference in meters I have a cheapy meter from sears looks just like the one mentioned in the previous few posts and on one pin I checked was 188 v but with the cheapy meter it showed 203 v that’s a 15 volt difference wow I have to check all voltages again.

Well there is a difference in meters I have a cheapy meter from sears looks just like the one mentioned in the previous few posts and on one pin I checked was 288 v but with the cheapy meter it showed 203 v that’s a 15 volt difference wow I have to check all voltages again.



Uhmmm.... You know the difference between 203, & 288 is not 15......


Also, Impedance is AC resistance.

You can calculate the DC resistance, or see it's effect on a circuit under test
with a simple test. Take a known voltage source like a good 9V battery,
connect 2 - 1meg-ohm resistors in series, measure the voltage across each
with your meter, and see what the two numbers add up to. Too far away
from 9V and you know your accuracy is going away. Do the same test
with 10Meg-Ohm resistors etc. Up or down to know at what point you
will begin to get poor readings.....

EX. With the 10Meg-Ohm resistors you measure 3.5V across each, in this
case adding up to 7V. On a known good 9V source. Your meter is loading
the circuit and effecting the accuracy of your work.

This was a bigger problem with needle type meters that were 20K-Ohm/Volt.
resistance loading on a DC scale. Most had it printed on the meter face so
you knew when to suspect meter loading. Most Digital meters are very high
input resistance to DC.


.

Typo it’s 188v

I’m going to try a new damper but I actually have both boost voltages if the damper is bad I shouldn’t have these voltages so that brings me to what are the bars on the screen that look like a bar generator but it’s not.

Ever since I accidentally let the hot red plate for like 40 seconds this is what I’m left with. Does this look like a bad damper. I am going to try a damper but I have both boost voltages so what’s this it looks like a bar generator but it’s not. Stumped again.

This is some kind of interference. A 4X multiple of the Horiz Osc. Perfect bars
like that are from some Osc, you can see they are perfect repeating not waving
or anything like that. What happens when you change the Horiz. Hold?
Is it always there? Does not look like a bad damper. If you got good Boost V.
Damper is most likely good. But with respect to the bars, On the outside, could
possibly be Heater-Cathode leakage, or short? Just a guess.....

Unfortunately, this might be a job for Mr. Oscilloscope.....

Some frequency getting into video? Does it remain or change
with Brightness, or Contrast change...?



.

This is some kind of interference. A 4X multiple of the Horiz Osc. Perfect bars
like that are from some Osc, you can see they are perfect repeating not waving
or anything like that. What happens when you change the Horiz. Hold?
Is it always there? Does not look like a bad damper. If you got good Boost V.
Damper is most likely good. But with respect to the bars, On the outside, could
possibly be Heater-Cathode leakage, or short? Just a guess.....

Unfortunately, this might be a job for Mr. Oscilloscope.....

Some frequency getting into video? Does it remain or change
with Brightness, or Contrast change...?



.

But this is what is bugging me

between the last pic posted and this
http://videokarma.org/attachment.php?attachmentid=204907&d=1664286524

http://videokarma.org/attachment.php?attachmentid=204921&d=1664977314
there has been 10-15% width lost.
which is strange
is the horz frequency way off? or the Damper damaged?

This is some kind of interference. A 4X multiple of the Horiz Osc. Perfect bars
like that are from some Osc, you can see they are perfect repeating not waving
or anything like that. What happens when you change the Horiz. Hold?
Is it always there? Does not look like a bad damper. If you got good Boost V.
Damper is most likely good. But with respect to the bars, On the outside, could
possibly be Heater-Cathode leakage, or short? Just a guess.....

Unfortunately, this might be a job for Mr. Oscilloscope.....

Some frequency getting into video? Does it remain or change
with Brightness, or Contrast change..?



. nothing changes it’s just there bright contrast horizontal nothing changes I tested all tubes although I can’t trust a tester anymore this don’t make sense I made k1 and put it in and while checking voltages that when I noticed the tubes red and that’s what was on the screen so I since put the k1 back in the way it was and still got these lines and I tried both hot new ones.

Now this don’t make sense using the cheapy dvm on the 200v scale pin 3 of v6 is showing 25.6v and with the other dvm it shows 8.3 so chances are the right reading would be the cheapy meter but 25.6 it supposed to be 2.5v

You say you “put in a new K1 and was checking voltages” when things got all weird, when did the screen start to do that?

After the new K1 put in, or after it was in AND you started checking voltages?

You say you “put in a new K1 and was checking voltages” when things got all weird, when did the screen start to do that?

After the new K1 put in, or after it was in AND you started checking voltages?

I had it on the bench and put in k1 and I checked voltages on the bench then put it in to find those bars but I since took k1 out only to find I put of all things a 680ohm instead of 680k so the original k1 is in now but still with k1 in and being wrong resistor initially I had no bars it seems more that the hot got red.

That was... bad.

You will prob have to meticulously go over the IF section checking every resistor and coil for damage, V6 area included, if you remove 3rd IF V3, do the bars go away?

I had it on the bench and put in k1 and I checked voltages on the bench then put it in to find those bars but I since took k1 out only to find I put of all things a 680ohm instead of 680k so the original k1 is in now but still with k1 in and being wrong resistor initially I had no bars it seems more that the hot got red.

Are you testing voltages “on the bench” without the yoke, crt and other cabinet mounted components being plugged into the chassis? :scratch2:

jr

Even with that wrong resistor I still had a full screen now vertical is collapsed. I don’t get it I never touched anything to do with vertical oh and I put the damper in but with no vertical I don’t know what’s happening now. Time to have a bon fire featuring Motorola

loss of 640v boost would cause vertical to fail.

Or the 6cg7

Ok vertical is good now so 1st IF no change 3rd IF still got the bars

If your looking to get rid of the bars, I think I would look to the Video Amp,
Video Output, Blanking amp. Not sure I would look in IF for this....

You can yank individual tubes, see if it goes away..... If you still have them
yanking 3ed IF, then it's after that....

In this case, it's good to have a tv with Parallel filaments, just yank one,
and see if you get a significant change....


.....

If your looking to get rid of the bars, I think I would look to the Video Amp,
Video Output, Blanking amp. Not sure I would look in IF for this....

You can yank individual tubes, see if it goes away..... If you still have them
yanking 3ed IF, then it's after that....

In this case, it's good to have a tv with Parallel filaments, just yank one,
and see if you get a significant change....


.....
Have you seen the pic posted with the bars on the previous page.

http://videokarma.org/attachment.php?attachmentid=204907&d=1664286524

http://videokarma.org/attachment.php?attachmentid=204921&d=1664977314

I have seen both of these....


.

Oh ok what would make such clean still bars like that I’ve never seen that before.the top pick has bars also but on that top pic if I inject video it looks ok but now I don’t think it would work injecting video now.

Nice clean steady bars like that I would guess are from the Horiz. deflection circuit
getting into the video somewhere..... Either it's picture information with a Dark bar,
or it's a white bar with picture information in between..... What's it look like to you?

Is the light, or dark area got some noise in it?, then the one more solid is the intruder.

At any rate, you are going to have to look back at what you recently did to see if some
part is touching something it's not suppose to...

Since it's well sync'ed to the horiz. to lock like that, it's from the horiz. section of the tv...



.

Well I already pulled all 3 IF tubes and was still there so I guess I’ll be pulling other tubes hopefully I can get this fixed already.

I think you need to look past the IF section for this.... Video Amp, V. Output,
Blanking, that area..... Yank a tube see if it goes away, if so, it's around that area.
Or at least that may be where it's getting in....

.

I don’t know if this would have anything to do with the video and the bars but the focus wire in the crt plug was burned and I had another wire with the end on it so I simply replaced it but the old one I had to dig it out of the plug the hole where the wire fits was kind of beat up but it went in ok but is it possible that it carbon tracked in the plug enough to short to the next pin to it.

I would imagine the focus voltage is pulsed DC at 15Khz, and can possibly be able
to produce bars like that if carbon tracked over to a common K, or G, point.

I had a tv once with Heater to Cathode short or leakage, don't remember how
shorted it was, But it produced white hum bars that floated upward through the picture
similar, but opposite to the black bars you might see in a bad power supply filter cap.

That one I found using the resistance measurement table in the Sams.



.

I know it’s a long shot but it’s worth a very close look at the crt socket and I know the focus wire is kind of separated from either side pins there is a space on both sides of the focus wire and this wire was burned and melted in the socket so it would be nice to find carbon tracking.

Ok no problem with carbon tracking on the focus wire so in pulling all tubes the only one that made a difference was v19 1st chroma band pass amp. Tube pulled no lines tube in with lines.I hope whatever the problem is it’s the reason for no video maybe this is corrupting the normal video path.

The lines are still there with V19 removed, they are just harder to see, as you loose H-BLANKING, and the screen looks over-driven.

Not only is there the weirdness of the dim screen with reduced width, the bars seem asymmetrical, a bit wider on the left than they are on the right.

Almost as if there was some kind of noise / ringing going on in the bias supply, 385v, as Squirrel boy said, “this might be a job for Mr. Oscilloscope”

Things unknown.

What is causing the loss of horizontal width?
Where are the bars from.
Is there a problem with power? (diode/cap fail causing noise , ripple )
Is the horizontal oscillator at the right frequency and correct waveform.

I know it’s a long shot but it’s worth a very close look at the crt socket and I know the focus wire is kind of separated from either side pins there is a space on both sides of the focus wire and this wire was burned and melted in the socket so it would be nice to find carbon tracking.

Very much worth a close inspection, did you replace the socket?
Also did you check for broken/ open wires to the crt socket.

jr

I am still of mind that the loss of width is a key to the problem somehow, just what is going on exactly, I'm not sure.
http://www.videokarma.org/attachment.php?attachmentid=204891&d=1663858736

There is a noted loss on both left and right sides of what he had before of about 1/2 inch with or without any video input.

this just can not also be related to the bar issue.

Blanking tubes can cause some strange problems. Try one ( 6BL8 ? ).

CRT sockets often go bad on the focus pin. Especially with excess F
voltage over time. They usually smell, problem is the spark gap.
Sockets are all pretty much the same. ! K resistors then the CRT
connection & the spark gap. Sub almost any to test BUT be sure its
off a high focus ( 6KV ) set.

As I remember no scope or analist. Means you you cant trace or inject.
In the day almost every set was fixed with just a Simpson 260 BUT
once in a while you had to get out the big guns.

Zeno:smoke:

Blanking tubes can cause some strange problems. Try one ( 6BL8 ? ).

CRT sockets often go bad on the focus pin. Especially with excess F
voltage over time. They usually smell, problem is the spark gap.
Sockets are all pretty much the same. ! K resistors then the CRT
connection & the spark gap. Sub almost any to test BUT be sure its
off a high focus ( 6KV ) set.

As I remember no scope or analist. Means you you cant trace or inject.
In the day almost every set was fixed with just a Simpson 260 BUT
once in a while you had to get out the big guns.

Zeno:smoke:

I disconnected the focus wire altogether.

I am still of mind that the loss of width is a key to the problem somehow, just what is going on exactly, I'm not sure.
http://www.videokarma.org/attachment.php?attachmentid=204891&d=1663858736

There is a noted loss on both left and right sides of what he had before of about 1/2 inch with or without any video input.

this just can not also be related to the bar issue.

I went over everything I did which was not much just a lot of checking nothing touching anything I have a hunch I have another bad cap.

Hi!

I'm wondering about this pic:

http://www.videokarma.org/attachment.php?attachmentid=204891&d=1663858736

If that extra bright vertical area in the center of the picture is not from the camera
then there may be some timing issue going on with the damper circuit.
But right now I don't think you should do anything about it......

Removal of the 1St Chroma Bandpass Amp Tube V19 Could mean the bars
actually do originate somewhere close. If you look at the Oscilloscope pics
on the schematic of the plate of V19, (Pin 6) you can see a burst group of spikes
for each scan line, This could be your bars if possibly the Burst Osc is not
at the correct frequency, Or this circuit, or any circuit in this video, or Color
processing area is not operating correctly.

You will have to start by checking voltages on each of these tubes......
Put it on a post Pin X, Expected Reading, Actual Reading. Lets All See them.


The Specs .pdf posted a few pages back of one of your meters, and at this
point I'm not sure which, or how many you have, but anyway one of the
meters said it is made to operate within 40 - 4Khz when measuring AC,
I believe..... So be aware the Horiz. circuit is 15Khz, and the color circuit
is some digits above 3Mhz, A question for Cheap-O-Meter accuracy....?
Same for clamp AC Current meters..... Is the clamp picking up 15Khz High
voltage stuff? is it effecting any readings...?

Not sure about the width of the bars makes a big deal not or not. Definitely
could be a decaying "ring" off the Horiz circuit making it's way to the video
or color circuit somehow..... Not ready to put any money on it today...

You have your hands full here..... I'm starting to like the fire idea you floated
a day or two ago.
You know Monday is a holiday.... You might just wanna drag this thing out to
the field behind your house, set it on fire, bring out some Marsh Mellows, a
few hot dogs, and make an afternoon of it.
Post a few pics so we can all celebrate the demise of this thing..... :D



end transmission....


.

Hi!

I'm wondering about this pic:

http://www.videokarma.org/attachment.php?attachmentid=204891&d=1663858736

If that extra bright vertical area in the center of the picture is not from the camera
then there may be some timing issue going on with the damper circuit.
But right now I don't think you should do anything about it......

Removal of the 1St Chroma Bandpass Amp Tube V19 Could mean the bars
actually do originate somewhere close. If you look at the Oscilloscope pics
on the schematic of the plate of V19, (Pin 6) you can see a burst group of spikes
for each scan line, This could be your bars if possibly the Burst Osc is not
at the correct frequency, Or this circuit, or any circuit in this video, or Color
processing area is not operating correctly.

You will have to start by checking voltages on each of these tubes......
Put it on a post Pin X, Expected Reading, Actual Reading. Lets All See them.


The Specs .pdf posted a few pages back of one of your meters, and at this
point I'm not sure which, or how many you have, but anyway one of the
meters said it is made to operate within 40 - 4Khz when measuring AC,
I believe..... So be aware the Horiz. circuit is 15Khz, and the color circuit
is some digits above 3Mhz, A question for Cheap-O-Meter accuracy....?
Same for clamp AC Current meters..... Is the clamp picking up 15Khz High
voltage stuff? is it effecting any readings...?

Not sure about the width of the bars makes a big deal not or not. Definitely
could be a decaying "ring" off the Horiz circuit making it's way to the video
or color circuit somehow..... Not ready to put any money on it today...

You have your hands full here..... I'm starting to like the fire idea you floated
a day or two ago.
You know Monday is a holiday.... You might just wanna drag this thing out to
the field behind your house, set it on fire, bring out some Marsh Mellows, a
few hot dogs, and make an afternoon of it.
Post a few pics so we can all celebrate the demise of this thing..... :D



end transmission....


.
As for the voltages I’ll be looking into that and the line in the center if it’s possible it’s a damper I since put a new one in.

Well sams shows 140v on pin 3 of the hots there’s only 100v and the 10k 20 watt resistor is good tried 2 new hots still 100v the 330 resistors are good pulled the 6bk4 cap still 100v and the 385v source on the end of the 10k resistor is there so this flyback may be screwed and it’s new. If I pull both hots the voltage is ok on pin 3. Ok update problem solved I hope the bars are gone don’t know yet if I’ll have video that’s the next post.

If pin 3 of the hot is the screen grid as I suspect then it being low indicates excessive screen current.
Excessive screen current occurs when there isn't enough plate load. If the damper is weak or open the screen should say like that (it will be worse if damper or H out plate lead is open). Or if circuits that normally load the flyback are open or otherwise not drawing sufficient current (even a detuning in the yoke or other resonant circuit could cause this).

The flyback is probably OK...If the flyback had shorted turns the H output screen voltage would skyrocket above rated voltage. Basically the cathode emissions is split between screen and plate (the vast majority to plate). So if the plate takes less of the fixed cathode emission the screen takes up the slack, but if the plate takes more the screen gets less.

If I were you, located where you seem to be, I'd try to find somebody with a 100 MHz scope and a signal generator and make up a couple of bias boxes (9 volt battery and 100K or so pot across it and some clip leads, two separate outfits.)

Have the knowledgeable scope guy visit you and start at the antenna and get the B&W signal to the CRT, with the horizontal and vertical oscillators and outputs completely unplugged. The set should be on a variac set so the B+ is not too high and the filaments not too low.

Next try to get the horizontal (and boost) working, still with a signal getting through with the AGC still running on the bias boxes.

Also remember ... this has been said before but its good to be reminded: never, ever, run the horizontal ourput tube with the plate disconnected or no B+ on it and its screen at normal connection. Its OK to run the screen at something like 20 volts if you can find that somewhere. Usually one just unplugs the horizontal output tube.

I had a recalcitrant horizontal intermittent in my CT-100 and that's what I did ...
using the scope on the Horizontal circuit with the AGC set with a bias box showed that its was the oscillator part that was intermittant. It never identified the bad part so I replaced them all, all resistors included, a second time. That fixed it.
I would never ever have figured all that out without scoping with the AGC fixed.

Found a few problems corrected but the b+ hangs in ok but the 145 190 275 drop off like 20 - 25 volts on each I think it’s a lousy power supply cap the 450v 50uf and possibly the 450v 80uf I keep changing caps then it’s ok then voltage drops again then another cap I’m out of caps.

None of this makes any sense anymore turn it on and as the tubes light the 3 voltages drop and of course the hv is low and I subbed caps made no difference and no tubes are red plating except the hot tube sometimes upon turning on even with the low hv voltages are still very low. This is just crazy already.

Horizontal oscillator 6 150=169 3 150=169 2 1=0 7 10=.8 9 -15=-14 1 .5=.7 where is 169 coming from should be 150.

169 means the tube is not producing the nice spike to drive the Horiz. Output tubes
properly, Especially with the Cathode voltage so Low.

Low HV Probably from Poor Horiz. Output drive to G1's, If it's too high, HV will be low
and Tubes will overheat, and will take your Power Supply Voltages down....

You must have some intermittent poor operation of the Horiz. Osc Circuit.


There are a number of things going on, Osc. Possibly not working right, Causes
H Output to overheat, and brings down PS Voltages.... Get the H. Osc working
right, right frequency, right signal shape, Size, etc. FIRST.


.

Horizontal oscillator 6 150=169 3 150=169 2 1=0 7 10=.8 9 -15=-14 1 .5=.7 where is 169 coming from should be 150.

Was the yoke plugged in during these measurements?

jr

So, again this is being hamstrung by the lack of an oscilloscope, for the most part. :(

https://www.ebay.com/itm/144750448303?epid=96943489&hash=item21b3cc8eaf%3Ag%3AjfcAAOSwLgdjOxCo&amdata=enc%3AAQAHAAAAoGuziX6I412Ct%2B05HrWkdphDCXD YEYdPjPfZjNLHRKLTN7rY%2BWXqat0%2FJaBREWiBoN5jARHMV ctwHYozJFv1KyJrLkGNaRIgmoAGYnCGkmuXXh9%2ByFmnAr0UA aXeGs7KLYBnK7sN2Vo4I7zCY49IBRUq%2FYkWqp1zYJNBcRg73 Nf3Ok3NWTUxJNiGccH1guMpH11HESwscoSwytH1Jj1H0jI%3D% 7Ctkp%3ABk9SR7q346T4YA&LH_BIN=1

semi OK ones for the price, have a feeling it won't last long b4 someone them all.

Pin 1 of horizontal oscillator has a .5 cap that was 100v but I had put in a .5 630v would this make a noticeable difference. Pin 2 1v but I get 0v and pin 1 .5v I’m getting -7.0v

Pin 1 of horizontal oscillator has a .5 cap that was 100v but I had put in a .5 630v would this make a noticeable difference. Pin 2 1v but I get 0v and pin 1 .5v I’m getting -7.0v

what cap # is that on the SAMs? :O

C81 but the sams don’t show it in the arrows to identify where it is but it’s there. Another typo

C81 but the sams don’t show it in the arrows to identify where it is but it’s there. Another typo

Shown on the picture on page 5.

jr

C81 but the sams don’t show it in the arrows to identify where it is but it’s there. Another typo

SAMS shows it to be between r119 - r121 and has a tie to ground with r120.

thus I was a bit confused when you said "Pin 1 of horizontal oscillator has a .5 cap" to me that meant C78, :O

It would be helpful if you gave part numbers from the SAMS to make it more clear :P

that part of the circuit is for sinewave shaping, the larger value volt cap should not matter, BUT value and type WILL.

Yes that was my mistake sorry about that it was not exactly pin 1.

I had put a new flyback in this set whos to say it may be bad in some way or defective I would hate to put the old one back in to see if this helps.

well, until you find someone with an oscilloscope, or are able to get one, you are quite limited.

Username1 mentions that the horizontal oscillator of course is not running correctly and that it don’t seem to have the punch behind the oscillations which makes sense so if there are no resistors bad and voltages are present then the only thing left is caps oscillator coil which checks out fine and flyback the hots were changed as well. Right now I don’t have a scope so I’ll need to push on without it for the moment. And of course if the flyback is good caps make the proper speed and shape of the signal.

There are 2 560pf caps in the yoke what are some symptoms of a bad yoke.

Well I’m not one to give up but it’s altogether and still low hv pulling the 145 190 275 voltages down is it possible there is a problem in the panel that has the g1 control and the red green blue controls. I’m not finding any reason for this voltage to drop and I believe this is affecting the horizontal drive low voltage low or no horizontal drive. It needs 190v and 275v and they drop to far to support the oscillator.

What is a good low esr power supply cap 450v 100uf I have 2 sprague caps in the series circuit and that voltage stays up 385-390v but the other caps that supply 145 190 275 have got to be bad even though my cap checker shows good but in circuit they may be breaking down.

If you have replaced them already, you have virtually nothing to gain by replacing them again at this point, the problem is someplace else.

C3A, C2B, C3B, C2C,
https://www.mouser.com/ProductDetail/United-Chemi-Con/EKWA451ELL820MK45S?qs=GBLSl2AkirvjfonVkrybSw%3D%3D

https://www.mouser.com/ProductDetail/Wurth-Elektronik/860241175001?qs=sGAEpiMZZMvwFf0viD3Y3aZipiehufnXMr Tn5c%2FPQuuDkej1prphYw%3D%3D

https://www.mouser.com/ProductDetail/Nichicon/UCY2E560MHD?qs=isV%252BNJxyrb7%252B4mK8MOO7xA%3D%3 D

prob replacements.

“low esr” caps are really not the right kind for this area, and hard to find in the values needed, General Purpose Electrolytic Capacitors will do just fine here.

If you have replaced them already, you have virtually nothing to gain by replacing them again at this point, the problem is someplace else.

C3A, C2B, C3B, C2C,
https://www.mouser.com/ProductDetail/United-Chemi-Con/EKWA451ELL820MK45S?qs=GBLSl2AkirvjfonVkrybSw%3D%3D

https://www.mouser.com/ProductDetail/Wurth-Elektronik/860241175001?qs=sGAEpiMZZMvwFf0viD3Y3aZipiehufnXMr Tn5c%2FPQuuDkej1prphYw%3D%3D

https://www.mouser.com/ProductDetail/Nichicon/UCY2E560MHD?qs=isV%252BNJxyrb7%252B4mK8MOO7xA%3D%3 D

prob replacements.

“low esr” caps are really not the right kind for this area, and hard to find in the values needed, General Purpose Electrolytic Capacitors will do just fine here. ok I thought low esr caps were better I can’t imagine where this pull is coming from what is it in this set that’s going to pull 3 voltages down I did nothing to this chassis to suggest a major mistake and I can bet it’s the horizontal oscillator alone pulling everything down while still having hv even though it’s low.

ok I thought low esr caps were better I can’t imagine where this pull is coming from what is it in this set that’s going to pull 3 voltages down I did nothing to this chassis to suggest a major mistake and I can bet it’s the horizontal oscillator alone pulling everything down while still having hv even though it’s low.

a lot of reading about the subject.
https://www.avnet.com/wps/portal/abacus/resources/article/understanding-esr-in-electrolytic-capacitors/

Where it comes into play is higher frequency buck converter type power supplies, but in vintage stuff like this, it would really not help much at all at 60hz line inputs.

Once the TV warms up, and the 275, 190, and 140 volt supplies drop down, how far does each one drop?

Is the 385 volt supply constant or does it also drop a bit?

What is the current being drawn from each supply?

jr

Ok I was not waiting the 15 mins that they recommended because of the thermistor so in running it the 145 was 146 the 190 was 183 the 275 was 269 very close but here’s the kicker I pull the 6bk4 cap off no difference at all and I shut it down then after about a minute turned it back on and the voltages started dropping fast then all of a sudden they instantly jumped up To a good level again. It’s like a momentary short then it was gone. When they drop b+ stays good.

Ok, So there is still a problem with power supply voltages going up & Down...
Possible short, possible tube using too much current. Problem, current meter
does not measure above some unusable value....

http://videokarma.org/attachment.php?attachmentid=204949&stc=1&d=1665520444


Timmy you can make your current meter measure more current, but you gotta
make an adapter for it....

First, in the uploaded pic. Fig. 1 Just FYI this is the only way to measure DC
Current in any circuit. You have to cut the Current Path and insert the Current
Meter into the path.

Second, This is kinda experimental, Since you have 2 meters, you can select
one meter you want to use as your current meter for this tv. It needs to be
able to measure about 700ma max.

Fig. 2 shows the start of my experiment, Take your current meter - set it to
the current DC Scale you will be using, It needs to be the MAX Current, I believe
it was pretty low. If there is more than one DC Current scale, be aware you
will not be able to switch scales with this little mod...

Measure the resistance of the Amp-Meter set to the Current Scale you want to
use. Find this resistance, I believe it will be around 5 - 12 Ohms maybe less....

Find another resistor in your stash 1W or so, that is the same value. Put that
resistor across your current meter leads as in my Fig. 3 pic. This will
DOUBLE the range of your current meter in it's present scale, HOWEVER,
your meter will ACTUALLY be reading ONE HALF of the current passing
through it.... Remember Current in Parallel Resistors Divides according
to resistance..... So For Example, if your meter reads 10 Ohms, putting
a 10 Ohm resistor across the probes will give the measured current 2 Paths
One through the meter, and the other through the added resistor.....
Find the equation online to Add Multipliers to the meter's ability.... How?
5 Ohms in parallel with the current meter will 3X I Believe the meters range...

Once you build this circuit you will have to test it with known test circuit so
you know it's giving you somewhat accurate readings.....

Then, you can monitor current paths in this TV that may be using too much
Fossil Fuel generated electricity when you turn it off & back on and have all
those low voltage problems....

Hurry though, this blasted thread is approaching 50 pages.....


Good Luck....


.

The voltages when turned on drop instantly no time for a tube to conduct then it just spiked up voltages went right up almost to say a switch was switched from short to no short I still think this may be a ceramic disc to ground or otherwise.

Ok, So there is still a problem with power supply voltages going up & Down...
Possible short, possible tube using too much current. Problem, current meter
does not measure above some unusable value....

http://videokarma.org/attachment.php?attachmentid=204949&stc=1&d=1665520444


Timmy you can make your current meter measure more current, but you gotta
make an adapter for it....

First, in the uploaded pic. Fig. 1 Just FYI this is the only way to measure DC
Current in any circuit. You have to cut the Current Path and insert the Current
Meter into the path.

Second, This is kinda experimental, Since you have 2 meters, you can select
one meter you want to use as your current meter for this tv. It needs to be
able to measure about 700ma max.

Fig. 2 shows the start of my experiment, Take your current meter - set it to
the current DC Scale you will be using, It needs to be the MAX Current, I believe
it was pretty low. If there is more than one DC Current scale, be aware you
will not be able to switch scales with this little mod...

Measure the resistance of the Amp-Meter set to the Current Scale you want to
use. Find this resistance, I believe it will be around 5 - 12 Ohms maybe less....

Find another resistor in your stash 1W or so, that is the same value. Put that
resistor across your current meter leads as in my Fig. 3 pic. This will
DOUBLE the range of your current meter in it's present scale, HOWEVER,
your meter will ACTUALLY be reading ONE HALF of the current passing
through it.... Remember Current in Parallel Resistors Divides according
to resistance..... So For Example, if your meter reads 10 Ohms, putting
a 10 Ohm resistor across the probes will give the measured current 2 Paths
One through the meter, and the other through the added resistor.....
Find the equation online to Add Multipliers to the meter's ability.... How?
5 Ohms in parallel with the current meter will 3X I Believe the meters range...

Once you build this circuit you will have to test it with known test circuit so
you know it's giving you somewhat accurate readings.....

Then, you can monitor current paths in this TV that may be using too much
Fossil Fuel generated electricity when you turn it off & back on and have all
those low voltage problems....

Hurry though, this blasted thread is approaching 50 pages.....


Good Luck....


.

he now has a meter that can measure 10a :o

this one, to be exact https://www.amazon.com/Etekcity-Digital-Multimeter/dp/B09K7P86N7

Att Timmy!

http://suzaku.live-evil.org/1011221837.jpg

This Mostly OK working oscilloscope can be YOURS for the price of shipping + a probe that you can get on amazon!

all you have to do is PM me if you are interested! :yes: :D

Att Timmy!

http://suzaku.live-evil.org/1011221837.jpg

This Mostly OK working oscilloscope can be YOURS for the price of shipping + a probe that you can get on amazon!

all you have to do is PM me if you are interested! :yes: :D

:thmbsp::thmbsp::thmbsp::thmbsp::thmbsp:

If I still had the spare scope I sold a few years ago I'd have made the same offer.

Out here good Scopes can still be found at swapmeets and hamfest for $10 if you keep an eye out long enough.

I don’t understand why if v6 is pulled out the horizontal oscillator won’t run but put it back it runs but still low hv so I guess this whole crazy problem is between the horizontal oscillator and v6. If there is something interfering with the oscillator then it looks like only 2 areas pin 13 from the flyback and pin 9 to the sync amp.

Again, given the limited tools you have on hand, it's very unlikely that a complicated issue like this can be worked out.

It's like trying to play Jenga on a crooked table with your eyes closed.

Vertical sweep is dependent on the boost from flyback transformer, so that has to be working, high voltage is dependent on horizontal oscillation being correct and at the right frequency, amplitude and waveform, and if it's NOT , the horizontal output tubes can go into oversaturation, overload the power supply and rob power from critical systems, like the horizontal oscillator.
Or, something that controls the horizontal oscillator can be in play here, the signal shown on pin 9 of V12 is key to timing and control of the horizontal oscillator, generated by V10, I'm not sure what effect the removal of V6 has on V10, but the signal path goes that route.

But as I and others have been saying, with just DVMs, you will be very unlikely be able to crack this nut.

The 6bk4 has got a light blue color inside and pin 5 is 245v and pin 1 is 400v sams says both pins should be 360v and adjusting the hv pot don’t bring up the voltage on pin 5 maybe this is holding the hv down got a new damper in. And tried another 6bk4

A blue or green glow from a 6BK4/A/B/C is normal, it just means that you are getting a good dose of x-rays, and it would be advisable not to get angry at anything, unless you want to suddenly turn green, increase muscle mass by 300%, rip up everything you are wearing, and terrorizing everyone near you by grunting and growling at them in a primeval nature! :)

As for not being able to adjust the HV, if it was low to start with, this could explain why adjusting R11 has little or no effect, a test you may try is to REMOVE the cap from the 6BK4 and measure the HV at the point there, this disables HV regulation, so be careful not to let it arc.

If there is no significant rise in HV with the cap off, then the problem is not the regulator, but if it does go up, 22-24k or more, then it is the regulator, if you do see a rise in HV, limit how long you run it with the regulator disabled, as it will stress parts over time.

Ok so I have the chassis out again and I tried taking the cap off in the set 20kv no higher I have the yoke plugged in on the bench waiting a few minutes to warm up both boost voltages are there tried 3 rectifier tubes just won’t go above 20kv cap off or not again subbed some tubes nothing make a bit of difference the other voltages that we’re dropping don’t anymore since I wait for warm up. I even tried the 0039 and 0068 caps the old ones which are good still. The 140 at the hot is around 160v and the oscillator tube is still giving voltages that are to high 6 and 3 are 165v.

So if the frequency of the horizontal drive is off besides resistors, capacitors, tubes, horizontal coil, which tests at 85 ohms what else is there to look at maybe the flyback.

The frequency and amplitude and shape of the signal has to be right. Example, if the sign-wave at pin 2 of V12 is wrong, then the signal at pin 5 of the horizontal output tubes will not be correct, also, if that signal is not aprox 150v p-p, HV & sweep could be low.
Also, if the signals in/out of V12 are nor right, there could be a problem with synchronization.

So how is synchronization done when everything around this area is ok.

Phase-locked loop controlled oscillator.

Keyed off the sync pulses of the incoming video signal, shaped and processed by the SYNC SEP & SYNC AMP and passed on to the VERT MULT & HORZ AFC respectively.

However both of these have the ability to free run w/o need of control input in a randomized mode.
But in your case, horizontal section is having a problem doing this, there could be any number of things causing it, a resistor or capacitor that does not sit well with the circuit, even if they test OK, the wrong types can upset things, as been mentioned , it's a tuned circuit using feedback including the yoke, and the FBT, it's very easy to make it unhappy. Especially with dual horizontal output tubes...

I had mistakenly reversed 13 and 14 on the flyback and that’s where the bars came from I since made it right and the bars are gone so I don’t know if this has something to do with this hv problem

I’m going back at what I did I originally took the old flyback out and put the new one in and all was fine only no video then I thought maybe the fly was defective and put back the old one that is when I reversed 13-14 then put the new one back in again with the mistake on those 2 wires and had the bars but since fixed that and this is what I’m left with low hv.

That would have introduced a major feedback phase loop error.
I'm not sure now what it could have done in there like that with it out of phase. :(

All it is a 1 ohm coil I checked it and it’s good but really how much oh a feed back voltage could it have made to damage let alone to affect the horizontal drive.

Look at pin 6 on the convergence connector, to which it is also connected to, that is 300v ptp there, who knows what it could have done with that signal inverted.

What would be suggested is that you go over the entire horizontal circuit with a fine tooth comb and re-check every resistor and cap, and if they do not check within 10% replace.

Also, this can check caps for leakage to some degree, https://www.amazon.com/ALMOCN-Transistor-Resistance-Capacitance-Capacitor/dp/B08K2Z5BGR/ref=sr_1_6?crid=2YV2SGS3JW78N&keywords=Transistor+Tester+TFT+Diode+Triode+Capaci tance+Meter&qid=1665686744&qu=eyJxc2MiOiIwLjAwIiwicXNhIjoiMC4wMCIsInFzcCI6IjA uMDAifQ%3D%3D&sprefix=transistor+tester+tft+diode+triode+capacit ance+meter%2Caps%2C138&sr=8-6

but, out of circuit only :(

Those 2 connections are separate what I did was reverse the connections 13 didn’t go to ground

You said “you had mistakenly reversed 13 and 14 on the flyback”

This tells me that the windnding was putting out a signal 180 degrees out of phase from what it should have been.

The wire that should have been on #13 was on 14 and vice versa, this is what you are saying, right?

Then you should re-check the whole area.

I did check all connections on the flyback the 13-14 on the coil is top and bottom it was reversed within the coil 13 was not on ground it’s just how the wires are oriented the same as reversing a coil polarity to push or pull like a solinoid but it was reversed. I followed that 13 to 2 33k resistors are 35k and a 150k that’s 163k.

I did check all connections on the flyback the 13-14 on the coil is top and bottom it was reversed within the coil 13 was not on ground it’s just how the wires are oriented the same as reversing a coil polarity to push or pull like a solinoid but it was reversed. I followed that 13 to 2 33k resistors are 35k and a 150k that’s 163k.

again, that means it was out of phase, and you should check things.

Well then 150k at 163.7k is just about at max then.

I changed a few resistors still no change but the hot are to have 140v but I’m getting 190v would this still be the case of the drive being off.

All I can add is, perhaps you can try to do direct video input again at test point B, and hope to get it to lock on, perhaps the horizontal frequency is way off.

I really do not understand the way things happened here when last week the bar issue was first mentioned.

Snip/paste.
“I’m going back at what I did I originally took the old flyback out and put the new one in and all was fine only no video then I thought maybe the fly was defective and put back the old one that is when I reversed 13-14 then put the new one back in again with the mistake on those 2 wires and had the bars but since fixed that and this is what I’m left with low hv.”

“I had mistakenly reversed 13 and 14 on the flyback and that’s where the bars came from I since made it right and the bars are gone so I don’t know if this has something to do with this hv problem”

Why was it not mentioned back then that the FBT was swapped from the new back to the old when the bar issue started?
This just lead to mass confusion and had people looking to the wrong places for the reason for the possible cause.

It's really somewhat a mystery to me why it was swapped after it was shown to be OK with the direct video input done previously, the issue of not being able to get a signal in via the tuner is not related to the FBT, more so the front end, (tuner/IF).

Again, I'm not sure what having that winding hooked up reversed did, but it could not have been very good for the set.

Please be more straightforward about such things to avoid future confusion, had you said that the bars started after you put the old FBT back in, things would have been much more clear.

Remember how I was immediately suspect of the reduced screen width? Something was telling me there was something wrong there.

Ok so I put the old flyback back in and the voltage at the hot is now 130v other voltages are looking better on v12 v10 and maybe once the anode is on the tube it will show higher hv now with the reg cap off and warmed up I’m getting 24 kv so once the chassis is put back in hopefully the voltages level out I can’t expect to get perfect voltages with the Chassis on the bench. I would have expected the hv to rise to at least 30kv with the reg cap off.then again the crt acts like a capacitor so it will probably rise to 30kv.

So back on track hv very good after 15 minute warm up voltages are still not right
275=266 190=187 145=143 not bad but after it running additional 10 minutes the voltage drops off
275=255 190=170 145=130 and no matter where the voltages are still no video. Using the new dvm if I’m reading it right on 10 amp or the other amp settings it’s showing either 0.055 or 055 so I’m not sure if this means 550ma.

I did notice I get activity from all vertical controls except the vertical centering it does absolutely nothing no movement of the screen so I’m not having video maybe I Should look into vertical maybe the horizontal and vertical cannot sync because of a vertical problem. What could cause the vertical centering to quit while everything else works.

Using the new dvm if I’m reading it right on 10 amp or the other amp settings it’s showing either 0.055 or 055 so I’m not sure if this means 550ma.

That would indicate 55 mA...where are you reading current?

jr

That would indicate 55 mA...where are you reading current?

jr

Output of the diode
The last time I used my 500ma meter in the same place and it went to the end of the scale

Output of the diode
The last time I used my 500ma meter in the same place and it went to the end of the scale

Was the new meter set to “10” and the probes plugged into “com” and “10Amax” positions?

jr

Was the new meter set to “10” and the probes plugged into “com” and “10Amax” positions?

jr

yes it was

Should read “0.55” on the “10” scale if the current is 550 ma, recheck your readings please. Perhaps double check with the other meter, see if it still pegs.

jr

Yes I think when it was on 10a it was 0.55 I mentioned in a previous post I didn’t put the decimal

I have to again ask myself if I messed up with the power supply caps since there is 3 different voltages and I checked and double checked if I had maybe one of the 190 and 275 backwards that would explain everything like the 145v to the tuner that comes from a higher voltage with a resistor to drop it to 145v it don’t make sense to have 2 feeds for 190 and 2 for 275 I would think the 275 would have had 3 feeds and 190 have 1 because there is 24 arrow connections while the 190 only has 9 arrow connections but I’m going to go back and check these arrow connections again.

Can someone that has the Motorola ts907 schematic tell me what the letter z means it has a 275 arrow where would this be marked where it goes.

Can someone that has the Motorola ts907 schematic tell me what the letter z means it has a 275 arrow where would this be marked where it goes.

Z and W are connected to the CRT heater...the connection of the heater winding of the transformer to the 275 volt supply is to elevate the CRT heaters to a voltage near that of the CRT cathodes, to reduce the likelihood of s heater/cathode short.

jr

So if this is only drawing 550ma then the diodes should not be getting hot not warm but hot. Another mystery.

So back on track hv very good after 15 minute warm up voltages are still not right
275=266 190=187 145=143 not bad but after it running additional 10 minutes the voltage drops off
275=255 190=170 145=130 and no matter where the voltages are still no video. Using the new dvm if I’m reading it right on 10 amp or the other amp settings it’s showing either 0.055 or 055 so I’m not sure if this means 550ma.

The picture shown is a strong indication of a IF problem.

the alignment is most likely off, and is messing the video up.

Sams shows c1 and c2a in series which makes sense but this pic of the Motorola original schematic note the c1 and c2a is it me or is this showing 2 negatives together +— — + I have these caps in series like the sams shows.

clearly an error on the Motorola schematic.

Yes I do see that now sams is usually known for that

What I find odd is the voltages on v1 v2 210 on pin7 and pin 8 100 but I’m getting 198 pin 7 and 60 on pin 8 but if I pull v1 the voltages on pin 7 come up to 130

I could use any idea what would cause vertical centering to not work at all but all other vertical works hold, linearity, height, but no centering screen don’t move at all. The centering pot measures 1.5meg but sams shows it to be a 2meg.

I could use any idea what would cause vertical centering to not work at all but all other vertical works hold, linearity, height, but no centering screen don’t move at all. The centering pot measures 1.5meg but sams shows it to be a 2meg.

You have nothing to center on the screen, no video.
if there was something to see, then you would see the effect of the adjustment.

if you were to feed video in like before, then you would see it working most likely.

I thought the whole screen goes up and down not the image alone.

Pin 1 of 6cg7 is supposed to have 80v on it but it has a ridiculous 180v there this tv is full of surprises.

I thought the whole screen goes up and down not the image alone.

Unless you have vertical underscan you won't see it move without video, and even if you do it's possible the osc will have enough jitter free running that you won't notice.

That said sets with electrical centering control typically run a DC current through the yoke to control centering. The pot it's self could be bad or the circuitry feeding it. Before declaring it bad though, I would definitely confirm operation with video fed in.

I could use any idea what would cause vertical centering to not work at all but all other vertical works hold, linearity, height, but no centering screen don’t move at all. The centering pot measures 1.5meg but sams shows it to be a 2meg.

The vertical centering pot (R-16) is 10 ohm! It is shown on an output winding of the vertical output transformer (T-2).

jr

The vertical centering pot (R-16) is 10 ohm! It is shown on an output winding of the vertical output transformer (T-2).

jr

Yes your right I knew that lol my mistake

I wish I knew if someone fooled with the overall alignment of this set but if it has been messed with it can’t be to far out since I can make out some things on screen but of course it’s distorted.

Has anyone ever had a video detect germanium diode test good but be bad in circuit.

What you would see if your IF section was VERY messed up...
Absolute and total randomized garbage on the screen as you try to tune in something, wildly changing color (unless color killer is turned down), herringbone patterns that will react to fine tuning, but no real video info getting through at all.

You could try to replace the video det, but it most likely won't help as the problem is most likely before it.

So it seems you have 2 choices.

1)
Find someone nearby with the equipment and knowledge to help you debug and align the tuner/ IF sections.

2)
Rig it for direct A/V input, and bypass the front end for now using a easy to build video amp to match the level needed for the set.

Well I put a new video detect diode in certainly was not an easy thing to do so I’m going to try it and as for alignment there is only one coil that shows the slug was moved it’s the same coil where the diode is A4 so if that was messed with then if I’m careful I could turn the slug in or out counting the turns in or out and see what occurs I have nothing to lose at this point.

No difference but the video injecting still works and I did notice the ac waving in the screen for the first few minutes caps are good unless ac is getting in somewhere. The block lines are not in the picture the camera is causing the lines.

How can I stop the blue arc that is between the rectifier and the 2 wires for the 3 volt heater

Well at this point it doesn’t matter how much current this set is drawing because the 3 voltages are low again and I still think there is some stray voltage getting in somewhere affecting the video and the voltages. being the output diode gets really hot which I’m sure is not supposed to get this hot.

How can I stop the blue arc that is between the rectifier and the 2 wires for the 3 volt heater

inducted corona, mostly harmless, my hoffman colorcaster did the same thing, just keep the wires as far away from the tube as you can, I did this by cutting the bottom off an old pill bottle and putting it around the tube as a guide/form to keep the wires away from the tube.

Thought it may break the glass on the tube. Smell of corona is not bad it cleans the air.

Again, don't take the voltages listed in the SAMs as gospel, expect them to differ by some degree.
Your screen showing good video with direct input is a indication that power is stable.

As for the hot diodes, this is not suprising, they are under heavy load, but if there is doubt, replace.

As suggested before, these are cheap and much better than the OEM ones.

https://www.mouser.com/ProductDetail/Vishay-General-Semiconductor/BYV26EGP-E3-54?qs=kop3EGWU%252BIswqAM%252B4kkscA%3D%3D

With video injected the horizontal and vertical are good stable picture but I can’t imagine where the stray voltage could be coming from because obviously it’s still pulling the voltage down but it seems not all the time or even where to start to look. There is a 390 ohm resistor to ground I clipped it and it measures 390k the voltages are low in v1 v2 but if I leave the resistor off the voltages jump up.

My set has a 3A3-C, and the heater wires were getting a bit close and causing a blue glow, all I did was use a plastic spacer around the tube that was about 10-15% larger than it's diameter to keep the wires away, it's working perfectly.

Problem I have is I only have a 360ohm resistor not a 390ohm. I could try it see what happens.

R47? I guess you missed that when you checked resistors in the area before, but I did mention that the ones off the cathodes are the ones most likely to be bad for some reason.

Yes r47 is it me orange. Blue. Brown is 360 ohm correct? I don’t have a 390 but this meter just yesterday measured 360 ohm and the 390 in the set measured 390k .

360 is close enough to try, but do take a look at the markings on what is coming out, just to be sure there is not a production change.

390ohm is what’s in there 360ohm made no difference v1 v2 pin8 should be 100v but 60v on v1 and 55v on v2

the 6EH7s are new? & what was the voltage on pin 7 V 1 & 2 ?

I was thinking Matthew antenna input is not making it to the first IF because of a bad trap it supposed to measure 15k but it’s a 2 connection and to measure it I would think it would have to be turned and if I do that I couldn’t get it back.

I was thinking of a “worst case scenario”, but not being able to see and test it, there is no way to know.

This may be a case of the dreaded “silver mica disease” bad caps in the coils L4 L5, causing wrong voltages on pins 7 & 8, if true, then hopes of getting it working is very low.

6eh7 all new 2 sets v1 pin 2 7v v2 12v v3 pin 2 0

6eh7 all new 2 sets v1 pin 2 7v v2 12v v3 pin 2 0

the important voltage is pins 7 & 8 on the 6eh7 tubes.

Well those v1 v2 7-and 8 voltages are wrong and L4 and L5 shows they each have a .001 inside why couldn’t they be changed.

I looked inside there is ceramic caps in L4 L5 I would have to clip the ground to see if they are bad or shorted

Well those v1 v2 7-and 8 voltages are wrong and L4 and L5 shows they each have a .001 inside why couldn’t they be changed.

as others have said, unlike changing resistors, changing capacitors in the IF section = 100% chance of needing to align the entire thing end to end, you would be better of replacing the 3w/2w power resistors, even if they seem OK, that are feeding power to the coils before even thinking of touching any caps in the area.

as others have said, unlike changing resistors, changing capacitors in the IF section = 100% chance of needing to align the entire thing end to end, you would be better of replacing the 3w/2w power resistors, even if they seem OK, that are feeding power to the coils before even thinking of touching any caps in the area.

Well all I have to do is clip the ground on each cap it’s on the outside and I can then see if they are bad if they are then I’ll have to decide what to do after that. Those caps oscillate the coils correct ?

I looked inside there is ceramic caps in L4 L5 I would have to clip the ground to see if they are bad or shorted

it be best not to disturb them yet, I would try fresh power resistors first.

if they are messed with, it will shift the alignment.

Well all I have to do is clip the ground on each cap it’s on the outside and I can then see if they are bad if they are then I’ll have to decide what to do after that. Those caps oscillate the coils correct ?

they are part of an RC, circuit yes.

very delicate, the slightest touch can change it,

it be best not to disturb them yet, I would try fresh power resistors first.

if they are messed with, it will shift the alignment.

I would think it’s not likely that both would go bad at the same time. These resistors are heavy wire wound I have never seen one of these rise in tolerance.

3w resistors are rather cheap now, and much smaller and run cooler than in the 60s, replacing them all won't cost much more than $10, and make SURE 100% that it's not a resistor problem, which is a good thing to do before looking at caps IMOH.

Same as the 2 .001 caps what’s the likelihood of both of those caps being bad. They are ceramics and I’m surprised that it wouldn’t be mica caps in such a circuit.

Ceramics almost never fail and when they do it's usually in sweep circuits where they're being whacked with several KV worth of pulses, not <300VDC and <3VAC that the IF subjects them to...

If you are concerned about the ceramic caps in the IF leaking current I gave you great advice before... Temporarily stick a cap 100X the capacitance in series. It will stop DC leakage and the series capacitance will be almost exactly the same as the original part alone.

The bulletproof-ness of ceramic caps is a fact. The only defective one I ever encountered was inside the motor of a cassette player. The complaint was sporadic overspeed. The motor had a 3-segment commutator, with 3 tiny ceramic caps bridging the gaps between segments. One of the caps was leaky, and replacing it cured the speed problem.

Since you stated that the voltages on pins 7-8 of the V1-V2 are wrong, but the 6EH7s are NOS, and the problem is not a bias 275v problem and extremely unlikely to be disc cap related, then once again the best path is to replace the power resistors, no matter how they seem to check out.

List here.
main power diodes
https://www.mouser.com/ProductDetail/Vishay-General-Semiconductor/BYV26EGP-E3-54?qs=kop3EGWU%252BIswqAM%252B4kkscA%3D%3D

6.8k 3w (r40, r49)
https://www.mouser.com/ProductDetail/Vishay-BC-Components/PR03000206801JAC00?qs=LCMWAU1DZcwK0C0BKWoLFQ%3D%3D

2.7k 3w (r41, r50)
https://www.mouser.com/ProductDetail/Vishay-BC-Components/PR03000202701JAC00?qs=LCMWAU1DZcx07iWwtn4Z2Q%3D%3D

8.2k 3w (r39 , r48 )
https://www.mouser.com/ProductDetail/Vishay-BC-Components/PR03000208201JAC00?qs=LCMWAU1DZczmDP2a7TUHog%3D%3D

Yes, use all 3w resistors, they will be smaller then the ones replaced, and much more reliable.
In fact replacing all resistors in the IF may be the only way to get it working again, and even then, you may not be able to.

When using the ohms chart for tube sockets use with tube in or out.

When using the ohms chart for tube sockets use with tube in or out.

tubes in, but it does not really matter much, since only the heaters will alter the readings you may be taking, which will be low anyway, so if you do it tubes in via a test socket under the tube, or out, just probing socket alone, you should get same readings.

I’m getting a really bad reading on pin 8 of v1 should be 3200ohms 3.2k I’m getting 6.30k I figured I would check resistance on v1 and v2

It starts at 5k and slowly rises to 6.30k

I’m getting a really bad reading on pin 8 of v1 should be 3200ohms 3.2k I’m getting 6.30k I figured I would check resistance on v1 and v2

You are aware of the note “measured from the output of X2” that would be the cathode of the diode, before L54, and not ground, if this is what you are doing, then it's a good sign the power resistors are bad, but if you are measuring from ground, your readings are wrong.

The reading starts at 5k and rises slowly to 6.30k while it should be 3200ohms 3.2k

No I’m not measuring from ground I’m on the second diode which would be x2 output

No I’m not measuring from ground I’m on the second diode which would be x2 output

Then, that seems to point right at the power resistor networks I pointed this morning, replace all the 2-3 watts in the area, and the power diodes, cost from mouser, 10-15$

I’ll post the other resistance readings from v2 v3 because they are way off

As it has been mentioned before, by myself and others, your best hope to get this working is not to touch any capacitors in the area what so ever, and VERY CAREFULLY replace all resistors with 2% or better carbon film types, paying close attention to placement and lead dress, IE, try to make it look as close to the original as you can, and since technology has changed so much over the years and they have gotten smaller, it never hurts to go up one size in power rating, cause even if you do, what you are putting in will be physically smaller than what you take out, they are that much more efficient than the old ones.

Ok v2 and v3 are within good range only v1 is a problem
The only pin that’s not right is pin 8 should be be 3.2 but it’s measuring 6.30

R39,R40,R41 obviously, get all 3 in 3w, but I would not stop there, you should have R48,R49,R50 on hand as well in case. It would not hurt to change R22 as well.

I’m getting a really bad reading on pin 8 of v1 should be 3200ohms 3.2k I’m getting 6.30k I figured I would check resistance on v1 and v2

Did you measure from output x2, like it says in the note? :scratch2:


Edit
Never mind, I responded to an older post,I missed a page!

jr

Did you measure from output x2, like it says in the note? :scratch2:

jr

I already asked him about that. :D

R22 is a trap

R22 is a trap

my error, that's R38, I jotted down the "22" next to the right number! :P

I will tell you I have the chassis out on the bench but this circuit should do what it has to on the bench and I put an antenna input and the voltage goes up very little so it’s resistor time I doubt it would have made any difference it it were in the set at this point

Ordered the resistors but I’m wondering where the 7 volts is coming from on v1 pin 2 it’s almost like the tube is locked on there for pulling the voltage down on pin 8 where on this tube is there something that would make it conduct or turn on full or partial.

I’m having a hard time believing those power resistors are bad because if they cannot supply the 100 v to pin 8 but only 60 v then I would think they wouldn’t be hot like they are working hard that’s why maybe the tube is partially on maybe not full but like an idle.

If I pull v1 the voltage go way up on v2 pin 8 but v1 pin 8 voltage stays the same low.

I’m having a hard time believing those power resistors are bad because if they cannot supply the 100 v to pin 8 but only 60 v then I would think they wouldn’t be hot like they are working hard that’s why maybe the tube is partially on maybe not full but like an idle.

R 39,40,41 form a voltage divider, your resistance check of pin 8 found a problem with it, so replacing all 3 is the next logical step.

I don’t understand why the ohms go up slowly from 5k to 6.30k why slow it’s like it’s filling a cap. There is the one resistor that goes to ground and I hope something is not grounding that is not supposed to be. And I have new 1n4007 diodes I had put in and made no difference.

On the Motorola it has 2 rectifier diodes is 1n4007 ok for this or is there supposed to be a fast recovery or anything special about these diodes.

On the Motorola it has 2 rectifier diodes is 1n4007 ok for this or is there supposed to be a fast recovery or anything special about these diodes.

the 1n4007 is a very old common diode that SHOULD work OK in the set, that is if you have a real one...

Problem is, over 60% of the ones out there are counterfeit junk and should not be used.

In fact, a few years back, we scrapped an entire lot of thousands of them cause they were all junk.

general rule is, anything not got from Mouser or digikey is not to be trusted when it comes to semiconductors.

as mentioned, a good choice is, https://www.mouser.com/ProductDetail/Vishay-General-Semiconductor/BYV26EGP-E3-54?qs=kop3EGWU%252BIswqAM%252B4kkscA%3D%3D

I bought a bunch of 1n4007 diodes but they look cheap so I’m not going to use them but I did try them they did work and like the output diode getting hot so did the 1n4007 also got hot so I put back the originals. So maybe it’s fine since trying to see what the ma was and it only showed 550ma so it’s not loading up.

What I find odd is with the resistors off pin8 there’s 138v and at the same time there is -7v on pin 8 and just touch the resistors to pin 8 and drops right down to like 63v where is this -7 volts coming from.

What I find odd is with the resistors off pin8 there’s 138v and at the same time there is -7v on pin 8 and just touch the resistors to pin 8 and drops right down to like 63v where is this -7 volts coming from.

This is not unusual, take a look at any given tube grid that is not pulled high to bias on a schematic, and you will note that they tend to have a negative voltage on it, so it stands to reason that if you float it, it will go negative.
Examples.

pin 2 V10B , pin 9 V12A

Well so much for the resistors they made no difference I kind of had a feeling the old ones were not bad. there is 132v there but soon as putting it on pin 8 it drops to 63v so something is going on here that I’ve yet to figure out. On v1 pins 1&3 are 15v and pin 2 7.25v it’s like the tube is locked on full pulling the 132v down to 63v. So I lifted the power on pin 8 it’s not the tube pulling the voltage down pulling the 8.2k ground drops the voltage. Then with the ground off I get the proper ohms.

Well so much for the resistors they made no difference I kind of had a feeling the old ones were not bad. there is 132v there but soon as putting it on pin 8 it drops to 63v so something is going on here that I’ve yet to figure out. On v1 pins 1&3 are 15v and pin 2 7.25v it’s like the tube is locked on full pulling the 132v down to 63v. So I lifted the power on pin 8 it’s not the tube pulling the voltage down pulling the 8.2k ground drops the voltage. Then with the ground off I get the proper ohms.


Hi!

Sorry, Our crappy internet service was off for several days.... If you have 15V
on the Cathode of tube V1, 6EH7 the 1St Video IF, then I would be wondering
what the plate voltage is? is the 275V source right, and is it 275V or lower?
Also what id the voltages on each side of R38, a 22 Ohm, R44, a 47 Ohm,
and R45, a 560 Ohm. Also what voltages are on both sides of R37, a 2.2K Ohm?

Please make these readings with everything hooked up.
Also are your power supply voltages back to what they should be?

.

Hi!

Sorry, Our crappy internet service was off for several days.... If you have 15V
on the Cathode of tube V1, 6EH7 the 1St Video IF, then I would be wondering
what the plate voltage is? is the 275V source right, and is it 275V or lower?
Also what id the voltages on each side of R38, a 22 Ohm, R44, a 47 Ohm,
and R45, a 560 Ohm. Also what voltages are on both sides of R37, a 2.2K Ohm?

Please make these readings with everything hooked up.
Also are your power supply voltages back to what they should be?

.
V1 pin7 193v
R38 14.92 14.35
R44 13.26 14.43
R45 13.45 0
R37 7.70 7.66
The 275v is around 280v other voltages are good on the ps. It appears that once the 8.2k goes to ground the voltage drops don’t have to be on pin 8 for the voltage to drop.

things to try.
swap V1 & V2 and see if voltages change.

resistance check of L4

pin 3-2 4-1 3-4 1 - gnd 2 to gnd.

Under 1 ohm swapping tubes don’t do anything I think there is something at ground pulling this down. This testing I’m doing with the tuner plug out chassis on bench tuner plug looks like it would not affect the voltage at pin 8.

If I knew the test path for resistance check I could probably find what’s happening here pin 8 to x2 output.

but do check the coil, if you have not yet, especially resistance between the windings and the windings to ground.

but do check the coil, if you have not yet, especially resistance between the windings and the windings to ground.

Then I have to cut all the connections the coil is wrapped on a plastic bobbin if I check resistance with connections on it will seek ground but with connections off there is no path to ground. The only ground is the .001 to ground I checked already.

Ok here’s what I came up with weather or not it turns out to be true I don’t know yet but obviously there is something invading the negative side so if it were shorting it would trip the breaker or burn the fuse wire so I’m thinking it’s something with cushion like a .1 or ,01 some or any cap to ground that is starting to short like the 2 in the power supply one on negative and one on positive there are 2 .01 caps there and several others I haven’t changed. After all the positive output diode is getting very hot and this is not right my other Motorola diodes never got hot it was a 908 chassis.

Then I have to cut all the connections the coil is wrapped on a plastic bobbin if I check resistance with connections on it will seek ground but with connections off there is no path to ground. The only ground is the .001 to ground I checked already.

you dont have to cut anything

http://suzaku.live-evil.org/resist111.jpg

measure the resistance between pin 7 of V1 and pin 2 of V2, it should test very high, if not infinite in resistance.

That is the most important thing to test.

you dont have to cut anything

http://suzaku.live-evil.org/resist111.jpg

measure the resistance between pin 7 of V1 and pin 2 of V2, it should test very high, if not infinite in resistance.

That is the most important thing to test.

It measures 23k and those coils did measure.1 ohm each.

It measures 23k and those coils did measure.1 ohm each.

seems OK, for reference, the same test on L5 should test about the same IMOH, if there was a coil short, the reading would be low.

you dont have to cut anything

http://suzaku.live-evil.org/resist111.jpg

measure the resistance between pin 7 of V1 and pin 2 of V2, it should test very high, if not infinite in resistance.

That is the most important thing to test.

seems OK, for reference, the same test on L5 should test about the same IMOH, if there was a coil short, the reading would be low.

So what do you think of the idea of a cap being a cushion.01 ?

So what do you think of the idea of a cap being a cushion.01 ?

or that 800pf?
but if it is one of those, as mentioned the alignment will be disrupted if replaced, so damned if you do or don't it seems.

your best way forward may be to rig for direct video input.

or that 800pf?
but if it is one of those, as mentioned the alignment will be disrupted if replaced, so damned if you do or don't it seems.

your best way forward may be to rig for direct video input.

I don’t think it’s the 800pf because there is no power source with it removed from pin 8 as long as the 6.8 is connected to the 8.2 and then grounded that’s when the voltage is lost

Hi

I believe measuring resistance from one side of the IF Coupling Transformers, or IF Coils
is not necessary, and you can achieve better results measuring voltages, like for example
Pin 7 of V1, and and Pin 2 of V2. If the Primary, & Secondary had some short, or leakage
it would show itself with 200V on one side, if the insulation were to break down at the
200V operating voltage it would show on grid of V2, and be more telling.

I'm wondering what the voltage on pin 8 of V2 is...? They are almost the same circuit,
and with almost the same voltages on all the same tube pins......
Same resistor voltage dividers too......

I'm also wondering if these voltages are a result of no signal from the tuner....

Have you tried hooking up your tuner subber to this tv & putting a signal on it
and leaving the tuner power plug hooked up to the tuner, but just removing the RCA
plug to the IF, & putting the Tuner Sub box in..... And then measure these voltages...?

.

Hi

I believe measuring resistance from one side of the IF Coupling Transformers, or IF Coils
is not necessary, and you can achieve better results measuring voltages, like for example
Pin 7 of V1, and and Pin 2 of V2. If the Primary, & Secondary had some short, or leakage
it would show itself with 200V on one side, if the insulation were to break down at the
200V operating voltage it would show on grid of V2, and be more telling.

I'm wondering what the voltage on pin 8 of V2 is...? They are almost the same circuit,
and with almost the same voltages on all the same tube pins......
Same resistor voltage dividers too......

I'm also wondering if these voltages are a result of no signal from the tuner....

Have you tried hooking up your tuner subber to this tv & putting a signal on it
and leaving the tuner power plug hooked up to the tuner, but just removing the RCA
plug to the IF, & putting the Tuner Sub box in..... And then measure these voltages...?

.

V2 is not the same with the voltage divider the 8.2k on v1 goes to ground but the 8.2k on v2 does not go to ground that’s the difference the ohms check perfect on v2 but v1 the only pin that was wrong was pin 8 and I have tried with the tuner plugged in and out with the subber and the voltage only went up like 4 volts. It’s something on the ground pulling the voltage down take the 8.2 off ground and voltage is good and also the x2 diode getting really hot not right. Iirc pin 8 was little higher then what sams says. Again pin 8 v2 don’t go to ground like v1 does.

Hi

Timmy, I understand what your saying about the 8.2K resistor. I Don't see any reason
for it except possibly biasing, or absence of signal from tuner.... If pin 8 on V2 has
100V on it, or 63, I'm just wondering what might be going on there that's all....

I don't have a good idea at this time for what you have now.... As for the hot diode,
if the power supply voltages are normal, I'm not sure I have an idea about that....


.

Well maybe I’m wrong completely about the voltages all pins hooked up pin 8 v1 63v v2 pin 8 55v maybe the voltages are supposed to be that until it conducts then it becomes 100v. Maybe it is a biasing problem I did check current with the resistor to ground versus not on ground and ma only went up 1ma with resistor on ground so I guess it’s safe to say it’s really not shorting.

As for the hot diode, if you have the replacements in there, as i pointed out before, there is a good chance they are counterfeit diodes, do not rely on them.
like seen here
https://www.eevblog.com/forum/projects/are-these-real-1n4007/


It would not hurt to put in 2a diodes like these,
https://www.mouser.com/ProductDetail/Vishay-Semiconductors/BYV38-TAP?qs=yIvl1B2wDi4ZFJ2%2F4Otccg%3D%3D
they WON'T get hot on you!

As for the hot diode, if you have the replacements in there, as i pointed out before, there is a good chance they are counterfeit diodes, do not rely on them.
like seen here
https://www.eevblog.com/forum/projects/are-these-real-1n4007/


It would not hurt to put in 2a diodes like these,
https://www.mouser.com/ProductDetail/Vishay-Semiconductors/BYV38-TAP?qs=yIvl1B2wDi4ZFJ2%2F4Otccg%3D%3D
they WON'T get hot on you!
Originals are in the chassis.

Originals are in the chassis.

then get 2 fresh 2A ones and then they will never get hot again! :D

$.70 each is worth it!

.70 is good yes but 7.50 shipping is not.

.


HOLY CRAP ! 50 Freakin' Pages !

Yah, gotts love under a dollar items & 10X that for shipping......


.

.


HOLY CRAP ! 50 Freakin' Pages !

Yah, gotts love under a dollar items & 10X that for shipping......


.

That’s for sure thing is I have bigger diodes but the numbers are worn off is there anyway to tell what they are

Pin 3 v1 64 volts add antenna 74 volts and if I up the gain the voltage drops highest voltage is with the gain at min I think this subber clock wise is low gain. I think I’m going to focus on v1 because voltage does go up on both v1 and v2 with antenna on so it is working but not enough. There are a few resistors a 22 ohm that measures 25 ohms don’t seem to high and the 18k measures 17.40k I’ll have to double check the 2.2k.

Good Morning!

I think you should try setting a goal of fixing this tv before this thread hits 60 pages!

Anyway.... Since you have that tuner subber, and it puts out TV type IF signal,
I think you should take the signal that comes out of it, and make a nice little
poker probe, with a coupling cap of course, and poke it around in the IF section
and see if you can narrow down where it works and where you loose it....
You did that video injection at Test Point 'B' a few pages back, so why not
take that IF signal from the tuner subber and poke it into each of the 3 IF
stages and see what you get...?
Don't forget to ground the ground part of the output cable, then just turn
the center wire into a capacitor coupled probe....

Aim for the G1's of each stage, put up some screen shots

1. no signal anywhere,
2. 1St, IF right at G1
3. 2Nd IF right at G1
4. 3Ed IF right at G1.

Naturally the signal will not be strong enough to produce a picture as you
get closer to 3ed IF, but the signal is what those circuits are tuned to
respond to, so I think it's your best bet to see at what point you might be
loosing your juice at...

Oh, and congratulations, your tuner subber is now also an IF section analyst
you can rename it later......


..

I have the chassis on the bench and I’m going by voltages and pin 2 of v1 I get same result nothing further up other then pin 2 I get the same with the subber plugged in. I have to check the 2.2k resistor again.

Does it appear that the k1 agc network would have anything to do with the IF functioning because I put together k1 and the only thing left that the IF would be lacking is the .4 source from the tuner because I have the chassis on the bench. Can’t find anything else obvious here.

Good Morning!

I think you should try setting a goal of fixing this tv before this thread hits 60 pages!

Anyway.... Since you have that tuner subber, and it puts out TV type IF signal,
I think you should take the signal that comes out of it, and make a nice little
poker probe, with a coupling cap of course, and poke it around in the IF section
and see if you can narrow down where it works and where you loose it....
You did that video injection at Test Point 'B' a few pages back, so why not
take that IF signal from the tuner subber and poke it into each of the 3 IF
stages and see what you get...?
Don't forget to ground the ground part of the output cable, then just turn
the center wire into a capacitor coupled probe....

Aim for the G1's of each stage, put up some screen shots

1. no signal anywhere,
2. 1St, IF right at G1
3. 2Nd IF right at G1
4. 3Ed IF right at G1.

Naturally the signal will not be strong enough to produce a picture as you
get closer to 3ed IF, but the signal is what those circuits are tuned to
respond to, so I think it's your best bet to see at what point you might be
loosing your juice at...

Oh, and congratulations, your tuner subber is now also an IF section analyst
you can rename it later......


..

in order to do that, you need to put the chassis in the " service position " as seen here.
http://suzaku.live-evil.org/0417191838b(1).jpg

OR pay way too much for a tube test socket like this
https://www.ebay.com/itm/363523910492?hash=item54a3b6ab5c%3Ag%3AKBcAAOSwrrZ hK-NA&amdata=enc%3AAQAHAAAAoE%2BGSLj1qOKFiUO6Mcu11gZAYJ% 2FgfSaUPH4kJOd6v2bBBgkt3NnX%2B%2BRDeffOpazae0LxwK3 AMYW87acjpmh4XwZw%2FllTQbPReglnHiLdOKjXanFOLLsn652 lLvTg2U76MkEWA3sA2nmA7JOgsckCQ2FpvlW%2Fw%2BEj3W6B3 T%2F2jIAHMp5J0%2FpKWolHyd4WKwIc5eekZ0oodGpzc%2FWrI rqG33U%3D%7Ctkp%3ABk9SR6aHwN2AYQ&LH_BIN=1

I know I wish I had those sockets and there is no way I can stand the chassis up to get access to the underside I tried already the harnesses are just to short

Can see an image. I can see words but video is just out of reach.

Well, I never had those fancy tube sockets.... I use to take 30 Gage wire & wrap it
around each tube pin I wanted to measure something on, then plug the tube back in
and I had access to whatever I needed on that tube....

But it would be best if you had a nice little bench you could put the chassis on, flipped
like that and make all your measurements....

Just build one, it's not like it's going to add significantly to the time it's taking to get
this tv working anyway..... And with all you spent on caps, precision resistors, tubes,
diodes, & thermisters, flyback transformers, you cudda just took out all that stuff and
put a flat screen in it already..... So just build a nice chassis table, put some movable
arms on it, mount a few lights, do it up nice!

Oh, and don't forget add one or two cupholders.....


.

Lol

The resistors I got I didn’t use the 2.7k because I got 2.7k 3watt but the voltage says they are rated for 135v so I’m not sure if it’s good to use them being there is 275v at one end. But I checked the 2.7k ones left in there and they show good however the others did not.

Problem here is I only put 2 resistors in v1 after not seeing a positive result got discouraged so after making a new k1 with the new 680k I put the chassis back in and was surprised to see an image and words I can read didn’t have that befor so now I put the other 2 resistors in v2 and I’ll try it tomorrow I still didn’t change the 2.7k in both because I screwed up when I got the resistors the 2.7k 3watt are only rated for 135v not sure if I should use them I don’t want to use them to have to pull the chassis again because they couldn’t handle the voltage and went high or opened.