I recently picked a Panasonic CT-1310M off the street. It's a commercial color CRT which accepts composite through a BNC jack and also has a VTR connector on the back, yippee! No listings on eBay for this model, barely any Google search results.
Once I got inside I'd noticed the 1.5A-125V fuse was blown so I replaced it, only to find it blew again when connecting mains power right after. Turns out the old HOT (Matsushita 2SD517) was blown & shorted out; I replaced it with the exact same part (new), left the TV set on with no signal (white screen) for a few minutes and the new HOT blew too. At that point I had one good HOT left since I ordered two. I replaced the HOT again but it blew once more when I tried adjusting the focus knob with the set still live.
Why does the HOT keep getting killed? I am currently waiting on a shipment of two new HOTs. Once I install another HOT I'll replace the safety capacitor for good measure and HOPEFULLY the HOT won't just blow again. Also it'd be nice to have the Sams' Photofact/Computerfact for this model as well.
https://i.ibb.co/pdNqkQ6/IMG-5986.jpg (https://ibb.co/QMh0xk7)
https://i.ibb.co/SfTmSF0/IMG-5987.jpg (https://ibb.co/z6c2dqb)
https://i.ibb.co/BLWRrPj/IMG-5988.jpg (https://ibb.co/K64HLG7)
https://i.ibb.co/9hzg1VH/IMG-5990.jpg (https://ibb.co/MfWStGk)
https://i.ibb.co/zVs6VmN/IMG-5991.jpg (https://ibb.co/whychdY)
https://i.ibb.co/mXztnrX/IMG-5992.jpg (https://ibb.co/D8KkBP8)
https://i.ibb.co/TknXtvv/P3050170.jpg (https://ibb.co/s2DSqmm)

Almost always its the FBT. Got a variac ? Run it up to @90 VAC while
watching the current. Normal is about 3/4 amp. if it goes higher
it will usually smoke & HOT will get hot. Obviously dont run long !
Also look behind the HOT for a little disc cap that likes to burn.

73 Zeno:smoke:
LFOD !

Check or replace any electrolytics around the horizontal driver transformer. Also, back in the day, counterfeit output transistors were sold, they looked good, but didn't last.

Check or replace any electrolytics around the horizontal driver transformer. Also, back in the day, counterfeit output transistors were sold, they looked good, but didn't last.
This is the one I bought, seems legit? https://www.ebay.com/itm/294368705463

Almost always its the FBT. Got a variac ?
No, I don't have a variac. Good luck finding a new FBT for this TV, and even if I did I'd probably shock myself trying to replace it...
Also look behind the HOT for a little disc cap that likes to burn.
Yeah it's this thing right here, the safety capacitor
https://i.ibb.co/2qMDBBZ/IMG-6117.jpg (https://ibb.co/BL6XRRn)
and like I said I'll replace it with this https://www.digikey.com/en/products/detail/vishay-beyschlag-draloric-bc-components/S152K47Y5PR63K7R/2356797 I'm keeping the diode since I can't find its datasheet so therefore no replacement.

You can also put a regular 75 watt bulb in place of the fuse.
Look up "dim bulb" on U tube.
Diode looks like damper. 99% of time they dead short.
BUT most are built in to HOT so be sure your replacements dont have a
built in one !
You may find a FBT but its a big gamble.

Zeno

it's in pretty rough shape by the looks of it. unfortunately, the commercial versions rarely have a sam's, but you might be able to find a consumer equivalent that has a fairly similar PCB in it.

any set i've worked on from that time period has always had a bunch of bad caps in it, and frequently bad transistors or even resistors in them. resistors that see a lot of heat can cook and die. anything anywhere around the deflection and power supply you should suspect and test

honestly wouldn't be worth it if you can't get the flyback, and you wanna test the strength of the tube as well

would be a real shame to spend a bunch of time and money fixing up a set just to find it has a dim tube, etc

it's in pretty rough shape by the looks of it. unfortunately, the commercial versions rarely have a sam's,
This model does have a Sams' but I'm not paying $22 for it. https://www.samswebsite.com/en/photofact/search/index/model/CT1310M
I should ask my library if they have Sams', I doubt they do though.
would be a real shame to spend a bunch of time and money fixing up a set just to find it has a dim tube, etc
From what I've seen while the HOT was alive the picture tube is still good.
https://i.ibb.co/DLzYBhk/vlcsnap-2024-04-02-16h04m04s624.png (https://ibb.co/jHbzCmG)
Image is monochrome because I accidentally had the 75Ω switch flipped on and ColorPilot off; the colorburst must've been decimated.
Image is blurry probably because of the above + focus was set wrong.
https://i.ibb.co/1zkqRPf/IMG-6115.jpg (https://ibb.co/CPf7VY5)
Here it is also with the 75Ω resistance on the composite signal but with ColorPilot on.
but you might be able to find a consumer equivalent that has a fairly similar PCB in it.
There's likely a consumer set that uses the exact same PCB since mine has empty traces where tuning circuits would go.

I have the Sams if you have any questions. Before you try another output transistor, resolder the driver transformer (T501) and any connections where a stake goes through the board and has a wire wrapped on it going to the output transistor. Also, resolder the flyback circuit board connections.

Diode looks like damper. 99% of time they dead short.

Yes that is the damper diode, and if it was shorted the HOT would blow instantly without giving a picture. I got my set to run fine for a few minutes until I killed the HOT by changing focus while the TV was on.
I measured the diode with the diode test mode on my multimeter. Few hundred ohms resistance in one direction if I remember correctly.

You can also put a regular 75 watt bulb in place of the fuse.

I don't have a lightbulb socket that'd make such a mod convenient. And what purpose would that serve? Fuse only blows when HOT is blown. Maybe you should smoke less weed (no offense)!

I have the Sams if you have any questions. Before you try another output transistor, resolder the driver transformer (T501) and any connections where a stake goes through the board and has a wire wrapped on it going to the output transistor. Also, resolder the flyback circuit board connections.

I'd be happy if you PM'd me the Sams' for this TV; these should all be on the Internet Archive anyways. Tomorrow I will check the resistors.

Would there be any danger in reflowing the solder on those components without discharging first? I don't have anything to perform a safe discharge at the moment. Maybe two old multimeter leads soldered together and wrapped in electrical tape will do, if they're rated high enough. I'd rather not get shocked.

I doubt that there's any shock danger if the set hasn't been powered on for a couple of days. After this length of time, the CRT would be the only charged item, maybe, that would only be a problem if you were to remove the high voltage connector. If it makes you feel better, any piece of wire bridged across the large electrolytics would discharge them. Zeno has a very good idea. Using a light bulb in place of the fuse would limit the current to the circuit, if the circuit is "normal", the bulb stays dim, an overload will cause it to be bright and you can remove power before another transistor is destroyed. Since the set does play for a "few" minutes, turn it off and feel if the transistor is cool or warm. After a few minutes if everything is normal, it should still feel cool. No shock danger as long as its off. Sorry, I don't have anyway to PM anything. I used to post diagrams on Videokarma, but they changed something and all it says is my images are too large.

I doubt that there's any shock danger if the set hasn't been powered on for a couple of days. After this length of time, the CRT would be the only charged item, maybe, that would only be a problem if you were to remove the high voltage connector. If it makes you feel better, any piece of wire bridged across the large electrolytics would discharge them. Zeno has a very good idea. Using a light bulb in place of the fuse would limit the current to the circuit, if the circuit is "normal", the bulb stays dim, an overload will cause it to be bright and you can remove power before another transistor is destroyed. Since the set does play for a "few" minutes, turn it off and feel if the transistor is cool or warm. After a few minutes if everything is normal, it should still feel cool. No shock danger as long as its off. Sorry, I don't have anyway to PM anything. I used to post diagrams on Videokarma, but they changed something and all it says is my images are too large.

You can mail me: luraichu2630 at gmail dot com. I felt the HOT right before it died, it was cold. I covered it with one layer of electrical tape to make touching safe even when live. e-tape is rated for up to 600v and that's the maximum voltage of the original HOT according to datasheets.

You can use imgbb to host pictures but don't count on them to keep your pics for decades. Also they like to add weird things to the end of their generated bbcode so make sure to remove it.

I got my set to run fine for a few minutes until I killed the HOT by changing focus while the TV was on.

The focus is meant to be changed while the TV is on.

Also, your pictures of the tube are not in any way conclusive as to it's health; a weak tube will still get bright, it just won't focus anymore at an acceptable level of brightness. Just be aware that you could be spending time and money trying to fix a set that will never look right

If you are just doing it for fun, and you're not that invested in the outcome, then great, but if you really are counting on it to look good in the end, you might want to skip this set and look for something cleaner that is obviously low hours

Besides all the important tips said here, is good anyway to check +B to see if it is too high, starting measuring the video output supply voltage (one pin of L351), if derives from flyback. Typically it have 180V, and above 200V is considered very suspicious.

See U tube for discharge vids.
You set is solid state. On turn off MOST of them bleed off in a few seconds.
It will not kill you, just teach respect. In fact in theory if you have an
irregular heart beat ( afibs) it may cure you ! Same thing as they do in
the hospital. ( cardioversion) I got bit at least once a week for 40 yrs and I am still here:banana:

The dangerous part of anything is where the AC comes in.

BTW I will take the weed thing with humor:D But I came from
South Acton, the beer side of town:beer: The pot heads came from West Acton
or Acton Center.

73 Zeno:smoke:
LFOD !

The focus is meant to be changed while the TV is on.
Well mine died the instant I'd touched the knob. If that's really the case, something is very wrong.
Also, your pictures of the tube are not in any way conclusive as to it's health; a weak tube will still get bright, it just won't focus anymore at an acceptable level of brightness. Just be aware that you could be spending time and money trying to fix a set that will never look right

If you are just doing it for fun, and you're not that invested in the outcome, then great, but if you really are counting on it to look good in the end, you might want to skip this set and look for something cleaner that is obviously low hours
This is mostly a challenge project; after all this is an obscure set and is worth some effort. I got it for free anyways! and I'd also like to be more comfortable working around high-voltage electronics.
Besides all the important tips said here, is good anyway to check +B to see if it is too high, starting measuring the video output supply voltage (one pin of L351), if derives from flyback. Typically it have 180V, and above 200V is considered very suspicious.
How exactly would I do this with my multimeter? also this measurement would require a new HOT. Two new HOTs should be arriving tomorrow & the new 1500pf safety capacitor arrived today.

ALSO it'd be nice to have the Sams' for this model.

About the measurement... yes, this one requires the system functioning. Is good to measure "in a hurry", with the + lead of the multimeter attached to the point (negative from multimeter will be to circuit ground, like the channel selector shield or some easy point), and then powering up the TV, watching as fast you can the measured voltage (before damage). Just when you are able to read the stable measurement, turn off the TV.
Then you can repeat for the HOT PSU, to take note. Same fast principle.

Is interesting both measurements, tyo see if one or both deviates from normal, to try to find soem culprit.

Another possible test, and more challenging, to check the PSU, is to remove the HOT and uses a resistor to emulate the HOT current, to independent test the PSU, before HOT eating. Some old PSU reacts bad to no load, hence the need for some load: some linear PSU rises the output voltage without load, making no-load measurement useless; and some older SMPS explodes without load.
A small lamp for emulating load... it depends, some PSU can be damaged by the filament in-rush current.

With all this going on I'm wondering about the horizontal efficiency capacitors, I've had many issues with these in older JVC production monitors over the years.

Besides all the important tips said here, is good anyway to check +B to see if it is too high, starting measuring the video output supply voltage (one pin of L351), if derives from flyback. Typically it have 180V, and above 200V is considered very suspicious.

Good call from Alex:yes:
To expand on that a cheap thing can be done. Follow the wire from L351 to the main chassis. On that line is a @4.7 mfd @350V. I can almost guarantee it
is bad & may be the problem. It can cause a lot of different symptoms
on ALL brands, its in the top ten of common fails. Also there is a SCREEN control on the CRT board. If to high it gives too bright a pix & poor focus.
Looking at the screen shots I see too bright a pix & poor focus. Too much
bright will draw too much current & stress the HOT.
Build a dim bulb tester. It will cost < $10 and will be very useful.
( socket, 2 alligator clips, some wire & a real bulb ).

enuf fer now
Zeno:smoke:

Thank you for all the amazing tips. I will try to find an old lamp to cannibalize as a bulb tester gizmo.
https://i.ibb.co/nCVFLZL/fuses.png (https://ibb.co/xHcN7P7)
If the +B turns out to be too high, at least we can crank it down with this variable resistor:yippy:

To expand on that a cheap thing can be done. Follow the wire from L351 to the main chassis. On that line is a @4.7 mfd @350V. I can almost guarantee it
is bad & may be the problem. It can cause a lot of different symptoms
on ALL brands, its in the top ten of common fails.

By this you mean a 4.7μF capacitor rated for 350V, no?

Found it. 4.7μF, lives near the HOT and is rated for 250V only. If the HOT blows again even with the brightness & screen turned down I will replace it.
https://i.ibb.co/z6XbSvk/thatfunnycap.png (https://ibb.co/dmP6QYh)

https://i.ibb.co/HdGSbdm/resist.jpg (https://ibb.co/m8hj28Q)
This is the screen potentiometer. which side is low/high? I don't wanna risk overloading the HOT with the wrong setting. Resistance is too high to measure with my multimeter.

I resoldered the pads for the FBT, driver transformer, and the HOT leads on the main PCB. I replaced the safety capacitor & HOT. I turned screen & bright all the way down. I did NOT use a lightbulb in place of the +B fuse. I didn't measure +B either. But I did catch the HOT death on camera, sadly. https://youtu.be/3RQW40rBP8s

Here is a frame-by-frame analysis of the HOT breaking down.
https://i.ibb.co/gMxpyTK/vlcsnap-2024-04-05-22h03m50s905.png (https://ibb.co/N6MPxjB)
https://i.ibb.co/mqYvws5/vlcsnap-2024-04-05-22h03m58s593.png (https://ibb.co/r6LbSP2)
https://i.ibb.co/ZJNGkBX/vlcsnap-2024-04-05-22h04m01s755.png (https://ibb.co/cvxk763)
https://i.ibb.co/wS4JwnZ/vlcsnap-2024-04-05-22h04m04s411.png (https://ibb.co/8r9zdyn)
https://i.ibb.co/FwdcXN3/vlcsnap-2024-04-05-22h04m07s651.png (https://ibb.co/qs2hCXj)
https://i.ibb.co/K561nG7/vlcsnap-2024-04-05-22h04m10s540.png (https://ibb.co/b61ft3L)
https://i.ibb.co/phhXPsf/vlcsnap-2024-04-05-22h04m13s370.png (https://ibb.co/PDDCYbc)
https://i.ibb.co/WgY6qSy/vlcsnap-2024-04-05-22h04m16s444.png (https://ibb.co/pJ9xGCz)
https://i.ibb.co/k1yD9M8/vlcsnap-2024-04-05-22h04m19s675.png (https://ibb.co/4dfSYJT)

I only have one HOT left. One chance to fix everything...
the +B adjustment knob is left on one extremity. so turning it the other way will either decrease +B voltage or send it through the roof.

The horizontal bands on the video were caused by me turning up the brightness. I turned it back down.

I installed another HOT. When I removed the old one which blew last night, there was goopy electrical tape around the transistor base. Maybe there was an arc.
https://i.ibb.co/ZgYkG7r/P4050045.jpg (https://ibb.co/vdQKVRW)
https://i.ibb.co/SrKDgd8/melt.jpg (https://ibb.co/FVBk10M)
This time around I tested +B. the TV had it set to 133VDC but turning the adjustment knob all the way to the right will bring it up to 140V. I tested by setting the multimeter to 500VDC range and putting one lead on ground and the other lead on the +B fuse.
https://i.ibb.co/RcWwQnt/b-adj.jpg (https://ibb.co/9Wj5yXB)

I should really replace the 4.7μF cap before doing anything else, no?
Could low +B voltage be causing a problem? You said it should be around 180VDC.

...yeah, I think a total recap is the way to go

Should I drop the lightbulb in place of the line fuse, or the +B fuse?

There is quite a pulse on that transistor case, you can't use layers of tape to replace the original mica insulator.

There is quite a pulse on that transistor case, you can't use layers of tape to replace the original mica insulator.
This is 3M Super 8 electrical tape. The HOT is rated for 600v max, so is the electrical tape iirc. Although it would explain the goopified tape around one of the HOT legs.
I don't have the original mica sheet. It was glued to the old, busted HOT with some weird white substance.

That weird white substance is the silicone heat conducting grease and without it the transistor could fail from overheating. Same stuff used on processor heat sinks and should always be used. The tape itself is not very heat conducting and its breakdown of 600V is the MAX at its nominal thickness not compressed under a transistor. There can be upwards of 1000V between the transistor case and ground during the flyback period and this is why it is so important to do things the right way, HOT's are not cheap as I remember and so far I've seen about half a dozen blown in this thread.

That weird white substance is the silicone heat conducting grease and without it the transistor could fail from overheating. Same stuff used on processor heat sinks and should always be used. The tape itself is not very heat conducting and its breakdown of 600V is the MAX at its nominal thickness not compressed under a transistor. There can be upwards of 1000V between the transistor case and ground during the flyback period and this is why it is so important to do things the right way, HOT's are not cheap as I remember and so far I've seen about half a dozen blown in this thread.
I'll have to correct you on that, I've blown a quarter dozen. They're $6 a pop, I can afford it...
But yeah this makes me feel pretty stupid. I guess I will try mounting the HOT externally just as a test to see if the previous mounting setup was bad.

What were the ORIGINAL HOT part numbers ?

The tape has to go ! Lets double check the ##'s then
clean it up spotless & get a mica insulator & compound.
On the U tubes I saw no reason for the fail looked
pretty normal.

Zeno

What were the ORIGINAL HOT part numbers ?

The tape has to go ! Lets double check the ##'s then
clean it up spotless & get a mica insulator & compound.
On the U tubes I saw no reason for the fail looked
pretty normal.

Zeno

The original HOT was Matsushita 2SD517. I got the EXACT same replacements from eBay https://www.ebay.com/itm/294368705463

I'm going to buy these two things on Amazon.

Mica insulator -> https://www.amazon.com/gp/product/B07P428VZ1
Thermal grease -> https://www.amazon.com/gp/product/B005VULWLA

The breakdown of the insulator to ground is going to kill the transistor. If I remember the heatsink was a ground potential on those Color Pilot sets, worked on may of them as they popular computer monitors in the 80s on the Apple-II that had a composite out.

Should I drop the lightbulb in place of the line fuse, or the +B fuse?

Being the supply in the vicinity of 120-140V, a 120V bulb will survive of and you can protect the PSU using it in the place of +B fuse, if have one. You can test the PSU even if HOT shortens out (if is a < 30W bulb).

For the entire TV, is good to use a higher wattage one.

Test only after aplying the correct insulator (mica) and thermal grease (+1 for correcting this first).

How much thermal grease should be used? It should be applied to both sides of the mica, right?

Yes, just a little dab is all that's needed on both sides then tighten the screws evenly allowing the thermal grease to squish out, this takes the air pockets with it.

Just to be on the safe side, is good to check or sub the pulse H cap (or resonating/efficiency cap). Is one generally having one pin to collector of HOT and another to ground (like the ceramic cap), in the board. It have values in the vicinity of 6 to 12nF, with at least 1600V of WV. A failure with that, and the HOT shortens out.

Just to be on the safe side, is good to check or sub the pulse H cap (or resonating/efficiency cap). Is one generally having one pin to collector of HOT and another to ground (like the ceramic cap), in the board. It have values in the vicinity of 6 to 12nF, with at least 1600V of WV. A failure with that, and the HOT shortens out.

I just checked the cap list I'd made, there are no capacitors in the TV that are in the realm of 1600v. I will check again since there are four 160v caps used and there might've been a read error.

I just checked the cap list I'd made, there are no capacitors in the TV that are in the realm of 1600v. I will check again since there are four 160v caps used and there might've been a read error.

This TV has ceramic caps on the HOT collector (red wire). Since they're not electrolytic, unlikely to fail IMO.
https://i.ibb.co/TYn8nZH/EFFCAP.jpg (https://ibb.co/7jTWTHG)

Are you willing to take that chance?

Are you willing to take that chance?
In my experience, only electrolytic caps manufactured in the 90s/Y2K go bad. I've never really seen a ceramic cap spoil, and even electrolytics from the 70s and 80s still hold up alright.
That said, I do have a single 1500pf @ 3000v ceramic cap lying around. I'm not sure whether the 700pf difference in capacity matters.
So YES, if the 1500pf cap isn't a suitable replacement I will try running the set anyways once the HOT is mounted correctly. I think I'll be very lucky if the HOT blows again; with the proper mica insulator and all - and new HOTs cost less than a bag of jerky anyhow.

Edit: don't just take my word for it, ask our mother ship https://audiokarma.org/forums/index.php?threads/ceramic-capacitors-ageing.820272/#post-11556769

I remember when HOTs were over $25.00 at Ness Electronics, as for ceramics I've seen those stacked units shift over time. I'm a 20 year member of Audiokarma and there has been a debate on & off over the decades. Regardless, I'm not into spending money on transistors just to blow them out on a chance that come capacitor is somehow going to behave, I grew up in a TV shop during the late 70's and early 80's and have seen plenty of magic smoke.

1) THOROUGHLY clean up tape mess
2) replace HOT & mica, compound each side & tighten evenly
3) remove B+ fuse & replace with dim bulb tester.

Now run the set watching it. The pix may be a little small and / or have
hum bars. Turn off & feel HOT every 5 mn for heat. Should be just warm.
Over current will brighten the bulb & lower HOT current. If that happens look
for a symptom, burning etc. If it runs an hour or 2 its probably OK.

This is old school BUT I remember going to a GE seminar @1975 & they
taught it for the same problem on the new SS sets, blows HOT instantly.

Zeno:smoke:

1) THOROUGHLY clean up tape mess
Did that, plus I recapped the TV yesterday. While recapping I found both 4.7uf caps had leaked. The one in the HOT circuit leaked so bad, one of the legs had disintegrated. I'm 99.9% sure THIS bad cap was the reason the HOT kept blowing!!
https://i.ibb.co/JzDCGTN/P4150056.jpg (https://ibb.co/qRTxc8z)
https://i.ibb.co/W6xjX9X/P4150057.jpg (https://ibb.co/hy7wN5N)
After the recap. Unfortunately as it turns out a few of these are actually bipolar, so I couldn't replace them as I didn't order any bipolar caps. Should I be worried about them?
They're marked "BP" in the image
https://i.ibb.co/9V7K1zS/after-recap.jpg (https://ibb.co/z7z9BjD)
I also got the mica insulators today but I still don't really have proper hardware for a bulb tester. Is it necessary?

Excellent!

About the bulb jig... is to be at safe side, due to incertainty about the flyback and PSU, to save potential HOT.

Is really possible to one of these subbed parts or the mica/tape being the culprit, but since is impossible in practice to test a flyback with DMM's, is important to consider the possibility.

Some wires, a bulb and it's socket is all needed.

Anyway, if you are very curious and wants to see it working ASAP:

Make sure to measure the PSU (the +B for HOT) at switch on with DMM already connected, to see if PSU is throwing too much voltage and promptly turning off the TV if is the case. IF the flyback is the culprit, the HOT will shorts again (so, some spare HOT is needed for this).

Late note: in fact, these bulbs are saved a lot of HOT and other parts for technicians using it, including myself.

Excellent!

About the bulb jig... is to be at safe side, due to incertainty about the flyback and PSU, to save potential HOT.

Is really possible to one of these subbed parts or the mica/tape being the culprit, but since is impossible in practice to test a flyback with DMM's, is important to consider the possibility.

Some wires, a bulb and it's socket is all needed.

Anyway, if you are very curious and wants to see it working ASAP:

Make sure to measure the PSU (the +B for HOT) at switch on with DMM already connected, to see if PSU is throwing too much voltage and promptly turning off the TV if is the case. IF the flyback is the culprit, the HOT will shorts again (so, some spare HOT is needed for this).

Late note: in fact, these bulbs are saved a lot of HOT and other parts for technicians using it, including myself.

I already measured +B. it sits around 133V at the lowest setting but you can crank it up to 140V

New HOT, new caps, new mica insulator... and the H lock is totally out of whack. aaand I somehow blew the HOT again. Video tomorrow.

I already measured +B. it sits around 133V at the lowest setting but you can crank it up to 140V

Is good to find the service manual or schematic with voltages, to be sure. For some TV's, 133V is fine, for others, is a lot (some works with "only" 90V; and I have one with 190V!).

New HOT, new caps, new mica insulator... and the H lock is totally out of whack. aaand I somehow blew the HOT again. Video tomorrow.

Is good to check the oscillator zone. If it generates too distorted pulse (too different from the correct waveform), also have a chance to eat some HOT.

Here is a video showing the lightbulb test and hsync garbage. https://youtu.be/8A4rwF6vGKM
Perhaps I might've broke something in the +B circuit/Horizontal circuit by running with too big of a bulb, though.
edit: Towards the end of the video, you can see the HOT disconnect. Slapping the set on the side gets it back on.
Is good to check the oscillator zone. If it generates too distorted pulse (too different from the correct waveform), also have a chance to eat some HOT.
I don't have an oscilloscope.

Slapping the set screams of bad solder connection, a very common problem with these.

Slapping the set screams of bad solder connection, a very common problem with these.
Yeah, but I don't see any bad joints on the board. What could be the culprit?

HVSD a.k.a High voltage shut down.
On most sets if it activates the set goes dead. On Panny, RCA Hitachi &
some others of this era too much HV causes the H osc to go off freq.
to reduce HV. Your set is probably like that.
133 volts may be OK but you need to see if it changes. Use a variac
or go from zero brightness to full brite. It must stay the same.
Cause I have seen was always the power supply. Also the B+ control
has to go lower @125 V to put the 130VDC in range.
A manual IS needed now.

Zeno

I guess it's important to mention the +B measurement was taken before the recap. It may be different with fresh caps.
Also the B+ control
has to go lower @125 V to put the 130VDC in range.
A manual IS needed now.
What do you mean? Last time I checked +B the lowest it could go with the adjustment pot was 130V. Max was 140V. But like I said, it may be different after the recap. I sure was foolish not to recheck +B.
I've been corresponding over email with someone who has a physical copy of the Sams' for this set. I asked them to send the part that shows the normal +B voltage and the H osc circuit.

Why in the he$$ are you buying transistors from Ebay. 99% are junk

Why in the he$$ are you buying transistors from Ebay. 99% are junk
<vent>First off, why in the hell are you too big of a pussy to say "hell" without censoring it? Sorry for encroaching on your Christian beliefs:smoke:</vent>
Secondly, I buy only QUALITY, ORIGINAL parts. The HOTs I bought are 100% legit, old stock!! And eBay is only a marketplace, you can't just say all parts sold there are junk. That's like saying all the produce at a supermarket is rotten. Maybe at yours it is :D

Why in the he$$ are you buying transistors from Ebay. 99% are junk

+1 , Especially sellers Dalbani, Semitronus and ceitron, pretty much all counterfeit stuff. I stick to the old RCA SK, GE and ECG lines - all of them came before the Chinese dumpex of fakes eBay is so littered with.

In the 90s, Dalbani was a go-to, but in the early 2000s, they suddenly had every video jungle chip out there, all remarked counterfeits.

38+ years in the biz, and I can see a fake a mile away.

Really. Everything about the HOTs I bought seemed correct - except for the fact they were of a slightly different package type. The original had a flat top but what I bought came with a bulged top.
So, where would I get a "real" replacement? The original HOT installed was a Matsushita 2SD517.

For me, in the case of TO-3 Horizontal Outputs WITHOUT integral Damper Diode, I use the RCA bagged or boxed 2SD822. RCA bought them by the bucket loads from Toshiba to offer an OEM HOT - in the 1980s. Don't buy them loose or with a shiny top - all 1980s/original 2SD822 transistors were frosty finish. The bagged ones are best, as you can guarantee no swaps with fakes. BTW, all lot "3A" 2SD822s are fakes. Chinese vendors never switched lot codes, and a 2002 produced fake and a current fake, same lot number.

Of note: the later 2000s "SK Series" (no RCA logo) 2SD822s are suspect. Thomson bought and produced a whole line of supposedly OEM transistors, ICs, STRs, and STKs, but many were counterfeit from the get-go.

If you can't find a RCA packaged 2SD822, then go with the SK3710, ECG238 or GE-38, all of which were produced before the Chinese dumpex.

Nearly all of my replacement were bought 1981-1992, so I know my stock of parts is genuine. I can't say that for some servo amp MOSFETs and Transistors I have to buy for current repairs - it's a minefield. eBay simply ain't the answer - unless it's sealed bags from RCA SK Series, GE's Pro-Line Replacements, or ECG bagged / boxed parts. Replacement guide for each is on the Internet Archive site, so cross reference is at hand, free.

NTE has had a rash of fakes - mostly in their STK replacements, some audio power amp transistors and a bunch of their "commodity" (high demand) parts.

Off topic a bit, but still somewhat germane, beware of Motorola transistors bearing post 1999 date codes. As of August 2000, all Motorola production was spun off to OnSemi, with their logo appearing after that date. ONSemi PCN 10143:
"ON Semiconductor will begin the changeover from the Motorola logo to
the ON Semiconductor logo for packaging materials on May 15, 2000
and for part marking on July 15, 2000. This General Announcement
affects all ON Semiconductor part numbers.
Motorola logos will be removed from bar code labels and will not be
replaced with the ON logo (ON Semi bar code labels will be "plain").
For a period of time, you may receive mixed shipments of ON
Semiconductor and Motorola bar code labels, packaging and parts."

And yet, Dalbani will happily sell you a Motorola transistor bearing a 2004 (0420) date code:
https://www.ebay.com/itm/144102545290

Cheers,

I found one lot of open box 2SD822's on eBay for a better price than what I paid for the 2SD517's. https://www.ebay.com/itm/254620362049 Comes in original old stock boxes. Should I cancel the 2SD517's? Will the 2SD822 be a GOOD 2SD517 replacement?

The 2SD822 seems slightly weaker than the 2SD517. For instance, the 2SD517's maximum Collector-Emitter Voltage is 700v, whereas 2SD822's is 600v.
However, a 13" CRT is pretty small. The 2SD517 datasheet says it's "Designed for use in large screen color deflection circuits". Did the designers of the CT-1310M use a better rated HOT than necessary?

More of what was available in mass quantity for the best price in the day. When I was in broadcast those Panasonic 1310's were a staple in the edit suites and were more forgiving than the Sony to poor sync and other issues but they suffered from cracked solder connections mainly around the CRT socket pins and the row of power resistors in the supply chain. The connections may "look" good but in fact may have a slight hairline crack, this is common with TO-220 devices where the center lead expands more and pushes harder than the others being it's the collector and part of the metal tab, power resistors will dissipate a significant amount of heat through the leads. Any time there is thermal cycling there is going to be mechanical stress and you're dealing with 40-some year old wave soldered connections that were the minimum to make the set work then.
If all is well in the other circuits the counterfeit transistors should work just as well as the original.

I canceled my order of 2SD517's from ceitron. I'm gonna use 2SD822's instead.

More of what was available in mass quantity for the best price in the day. When I was in broadcast those Panasonic 1310's were a staple in the edit suites and were more forgiving than the Sony to poor sync and other issues but they suffered from cracked solder connections mainly around the CRT socket pins and the row of power resistors in the supply chain. The connections may "look" good but in fact may have a slight hairline crack, this is common with TO-220 devices where the center lead expands more and pushes harder than the others being it's the collector and part of the metal tab, power resistors will dissipate a significant amount of heat through the leads. Any time there is thermal cycling there is going to be mechanical stress and you're dealing with 40-some year old wave soldered connections that were the minimum to make the set work then.
If all is well in the other circuits the counterfeit transistors should work just as well as the original.

Never mind, then. I cancelled my order cancellation.

HVSD a.k.a High voltage shut down.
On most sets if it activates the set goes dead. On Panny, RCA Hitachi &
some others of this era too much HV causes the H osc to go off freq.
to reduce HV. Your set is probably like that.
133 volts may be OK but you need to see if it changes. Use a variac
or go from zero brightness to full brite. It must stay the same.
Cause I have seen was always the power supply. Also the B+ control
has to go lower @125 V to put the 130VDC in range.
A manual IS needed now.

Zeno
+B is supposed to be 130v. Sams' schematics courtesy of damen.
https://i.postimg.cc/25SRsrjb/Panasonicmonitor001annotated.jpg (https://postimg.cc/xXh4Hrzn)

Or there abouts, it's never spot on and will vary according to beam current and other factors.

What's normal HOT temp? It was warm last run, but that could be heat from the flyback.

Good question, I guess my rule of thumb is bath water warm but no more than what your fingers can tolerate for say 10-15 seconds. Sorry I can't put a number to this but the HOT itself is known to run warmer than the transistor in these.

New HOT, cleaned CRT pins & reflowed pads on CRT socket, and the TV is still doing the same shit (no lightbulb!). The picture starts normal but then gets too bright & loses H sync. At this stage +B is 131 to 132v. The colors get VERY saturated, and soon Green disappears followed by Red and Blue. Then all you've got is a bunch of monochrome garbage lines dancing across the screen. Sometimes, a bright colorful flash appears indicating something just disconnected. +B jumps to something like 139v in this state, and what once was a fluctuating whining noise becomes a monotonous high pitch. Orange filament glow disappears I think.
https://i.ibb.co/4sMdbZJ/P4220070.jpg (https://ibb.co/mvt8nCS)
Next to the flyback, there is a pot labeled "SUB BRIGHT". Should I bother?

Edit: Just did another test run. The picture lasted for a few seconds but then the magical flash appeared and +B dropped to 127v!

they suffered from cracked solder connections mainly around the CRT socket pins and the row of power resistors in the supply chain.
Row of a what now? "supply chain"? What am I looking for

Those big resistors just to the north of the B+ adjustment. Seriously if it was mine I'd go over every solder connection on the board with a touch of solder and replace all of the supply capacitors, they're 40 years old now and not getting any better.

Those big resistors just to the north of the B+ adjustment. Seriously if it was mine I'd go over every solder connection on the board with a touch of solder and replace all of the supply capacitors, they're 40 years old now and not getting any better.

It doesn't help that the nearly half-century old flux smells bad when heated. I already replaced all the electrolytic capacitors in the video circuit (sound circuit was left mostly untouched) - what exactly is a supply capacitor?

The capacitors that are involved in the power supply itself, replacing the caps in the video circuit have nothing to do with the power supply itself. Those would be the likes of C558, C805, C502, C307, C203, C564, C1603 & 1604 for starters.
I know that flux smells bad, been burning that stuff since the late 70's myself so I know where you're coming from but when you described having to hit the set and things started working that was the first clue to intermittent connections. The gradual shift to bright then loss of H-sync points to either a thermal issue that might be taking down a power supply line or a bad capacitor that's hogging current. You found that bad one over in the horizontal and while the 80's didn't have the "capacitorgate" they're still prone to failure due to their wet internal construction. Just the nature of them.
If the smell of the flux is that offensive it can be washed off using either acetone or isopropyl alcohol however the main board should be removed as these will damage the cabinet plastics.

Learning electronics isn't easy, after 45 years I'm still learning and getting off the ground can be really tough when you're dealing with a tough dog. Test equipment is essential but sometimes the best tool is the experienced gained over the years, best advice I can offer is to take it slow, read & study the schematics and stick with it. I started swapping tubes in old B&W sets when I was in the 3rd grade when Carter was in office. You will get there, problems are only opportunities in work clothes that are designed to bring you up to the next level. You CAN do it.

<vent>First off, why in the hell are you too big of a pussy to say "hell" without censoring it? Sorry for encroaching on your Christian beliefs:smoke:</vent>
Secondly, I buy only QUALITY, ORIGINAL parts. The HOTs I bought are 100% legit, old stock!! And eBay is only a marketplace, you can't just say all parts sold there are junk. That's like saying all the produce at a supermarket is rotten. Maybe at yours it is :D

well go ahead and buy the junk i was just telling you it is mostly junk as you have found out.

when you described having to hit the set and things started working that was the first clue to intermittent connections. The gradual shift to bright then loss of H-sync points to either a thermal issue that might be taking down a power supply line or a bad capacitor that's hogging current.
I think it may also be an issue of the tube drawing TOO much current. Because the picture looks brighter post-recap. Almost too bright. It actually gets less focused.
That's why I alluded to the Sub Bright pot. Perhaps we can see if running dimmer will stop the horizontal f*ckery. Then we will know if it's an undercurrent or overvoltage problem.
I'm tempted to think it is overvoltage, like zeno said.
Learning electronics isn't easy, after 45 years I'm still learning and getting off the ground can be really tough when you're dealing with a tough dog. Test equipment is essential but sometimes the best tool is the experienced gained over the years, best advice I can offer is to take it slow, read & study the schematics and stick with it. I started swapping tubes in old B&W sets when I was in the 3rd grade when Carter was in office. You will get there, problems are only opportunities in work clothes that are designed to bring you up to the next level. You CAN do it.
Thanks for the pep talk, although slightly unnecessary. :) I know I'll get the set in tip-top shape eventually.
My last and first recap was a Macintosh LC. The logic board required surface mount caps while the rottening power supply used through-holes.

New HOT, cleaned CRT pins & reflowed pads on CRT socket, and the TV is still doing the same shit (no lightbulb!). The picture starts normal but then gets too bright & loses H sync. At this stage +B is 131 to 132v. The colors get VERY saturated, and soon Green disappears followed by Red and Blue. Then all you've got is a bunch of monochrome garbage lines dancing across the screen. Sometimes, a bright colorful flash appears indicating something just disconnected. +B jumps to something like 139v in this state, and what once was a fluctuating whining noise becomes a monotonous high pitch. Orange filament glow disappears I think.
https://i.ibb.co/4sMdbZJ/P4220070.jpg (https://ibb.co/mvt8nCS)
Next to the flyback, there is a pot labeled "SUB BRIGHT". Should I bother?

Edit: Just did another test run. The picture lasted for a few seconds but then the magical flash appeared and +B dropped to 127v!

The #F002 will open if HOT shortens out, probably. If +B are not collapsing to zero V when image disappears*** (in fact it will rise due to R802), confirm measuring if HOT really shorted out. Perhaps only the oscillator can stopped due to some overload (try to run with brightness and contrast to minimum, normally this will suffice and not needs to adjust the sub bright).
Perhaps the screen grid (G2) are cranked up. Is interesting to reduce it to see that happens.

***if is the oscillator protecting something or faulty oscillator.

I think it may also be an issue of the tube drawing TOO much current. Because the picture looks brighter post-recap. Almost too bright. It actually gets less focused.


It will look less focused when the brightness and contrast is higher, that's normal. definitely turn it down to something that looks "normal" if it's gotten brighter after replacing caps.

I agree with the other post about the supply caps. Pull and test any electrolytics in the supply. That's 802 803 804 805 in the 130 V, 502 in the 12V, and all those other small voltages, C558 C203 C307 C564 C1603 C1604

Pay special attention to the caps shaded in grey

If you don't have an LCR meter, you can buy one of these cheapo component testers (https://www.ebay.com/itm/375292627205?itmmeta=01HW5S6N7HQXGSFB1H04ZW4SW8&hash=item57612f0905:g:bP0AAOSw12Vl5olp&itmprp=enc%3AAQAJAAAA4Ahf13fXDiI3N%2BlztE06bCYbH1E FP56iGHvPCOUre%2FfgtrVb4mnHCi1%2BX%2F46LhBT0qvfmUk cCVXBa2wp2LlJPrp36bsmCgJl2A4BJmnquImslLcft3BVb7WLp Yr5TJRztUgF1iNN6p1JROjtvnEAdtNEhpMaGZ4eh7TkAhdiMjM LctUV21%2B6ERJdVFpabDr69q0Dz4sMgr51j9z6u65EYGKC%2F uaEcTvLcQumvWUzu4M0izU%2B0WzyDwY0z5N247F6SqwD4vkb8 2ynexkcZ9vR%2BCpsdK26YY0q8Nut2XmlA1DZ%7Ctkp%3ABFBM iNSaueFj) off ebay or amazon (any of them are the same not just this link)

It's not going to be super accurate, and it can't go up super high in capacitance, but it will at least give you a go-no-go reference for telling if a cap is super high ESR or open or shorted in some way

Also you might want to test the supply transistors. Q801, Q802, Q552 You can either test each leg just to confirm they are functioning as transistors still, but those cheapo component testers will quickly tell you if they are probably still working or not as well

I was attempting to test the 160v supply. I measured the positive leg of C559 to ground, it was something like 140v. But then the HOT popped again. I am so sick and tired of throwing away money at new HOTs.
It will look less focused when the brightness and contrast is higher, that's normal. definitely turn it down to something that looks "normal" if it's gotten brighter after replacing caps.
There is no contrast control. Brightness is always at minimum. I turned down Sub Bright but the H sync still goes off.
Seriously if it was mine I'd go over every solder connection on the board with a touch of solder
I've done just that, reflowing the pads for the power supply, H circuit and some of the rest. That only seems to have made things worse. Now there is no color & white horizontal dots across the screen.
https://i.ibb.co/jZ2RtGM/IMG-6360.jpg (https://ibb.co/3YqzKWN)
I agree with the other post about the supply caps. Pull and test any electrolytics in the supply. That's 802 803 804 805 in the 130 V, 502 in the 12V, and all those other small voltages, C558 C203 C307 C564 C1603 C1604
Actually, I've probably already replaced those. The only caps left alone were in the audio circuit or were bipolar.
Pay special attention to the caps shaded in grey
None were grey?!
Also you might want to test the supply transistors. Q801, Q802, Q552 You can either test each leg just to confirm they are functioning as transistors still, but those cheapo component testers will quickly tell you if they are probably still working or not as well
I suppose it doesn't hurt to try.

I found a 12k Ω resistor (R804) in the power supply with paint peeling off. My multimeter says it's actually resisting 73000Ω.
https://i.ibb.co/D4FFm0y/P4230074.jpg (https://ibb.co/ZdrrvqP)

None were grey?!


Sorry, those caps shaded in grey in the Sam's. Grey means they are important, both in terms of failure and in terms of observing correct values when replacing

There is no contrast control. Brightness is always at minimum. I turned down Sub Bright but the H sync still goes off.

that's nuts. No contrast? I've never seen a set without contrast. It's also called "picture" on some sets, usually older ones. If you have no contrast or picture control anywhere on the set, then your contrast is controlled by the drive controls for the guns, of which there ought to be all three (RGB) if you really don't have any manual picture or contrast knob. but that just seems too far fetched

I swear there's no control labeled contrast. These are all the easily accessed knobs,

On the front of the case:
Bright
Panabrite
Tint
Color
ColorPilot (on/off)

On the right side:
Sharpness
V-Hold

On the neckboard:
Screen
Low Light Red
Low Light Green
Low Light Blue
Red Drive
Blue Drive

Panabrite=Contrast.

Panabrite=Contrast.

Apparently Panabrite changes both brightness and contrast.

Any clue as to why the color is gone after reflowing solder? Although, I should probably replace all resistors first. They're clearly going off-spec.

I found a 12k Ω resistor (R804) in the power supply with paint peeling off. My multimeter says it's actually resisting 73000Ω.
https://i.ibb.co/D4FFm0y/P4230074.jpg (https://ibb.co/ZdrrvqP)

My bad, I miscalculated the multimeter readout. It's actually 3550Ω, which is way short of it's original value of 12kΩ.

Should I replace just the power supply resistors, or ALL of them?

My bad, I miscalculated the multimeter readout. It's actually 3550Ω, which is way short of it's original value of 12kΩ.

Remove one leg and measure again, to be sure (if you don't tried to measure this manner). Possibly some other resistors are in current measuring path.

Should I replace just the power supply resistors, or ALL of them?

Normally, only the charred ones or with extremely bad original soldering due to overheating/thermal cycling. Measure some, and if all measure ok, don't need to continue. (again, is good to remove one leg to eliminate readings from circuit).

Pull and test any electrolytics in the supply. That's 802 803 804 805 in the 130 V, 502 in the 12V, and all those other small voltages, C558 C203 C307 C564 C1603 C1604

I replaced all of those except C1603 or C1604 since they were on the channel selector board. Best to do that while we're at it.

Normally, only the charred ones or with extremely bad original soldering due to overheating/thermal cycling. Measure some, and if all measure ok, don't need to continue. (again, is good to remove one leg to eliminate readings from circuit).
Dude, R804 has got to go. It's clearly gone sour and is probably bringing a supply line or component up too high.
Here's my replacement parts list for the important PSU resistors: https://www.digikey.com/en/mylists/list/PTPXQHEAGB ("Notes" column contains part numbers from the schematic)
I also have cap lists. I'll share them later, although I could not find a replacement for the one bipolar 3.3µF @ 160v cap that lives in the H circuit. They just don't make bipolar caps with that kind of voltage tolerance anymore.

Dude, R804 has got to go. It's clearly gone sour and is probably bringing a supply line or component up too high.


I think he just meant in general you don't have to test every single resistor. If you test a bunch that look okay, then usually all of them in the same area and/or of the same type will be okay. The main thing to look out for is burned or otherwise darkened areas on the PCB or the resistors themselves. Usually newer resistors (post 1960s or so) don't go bad unless they burn up.

I will add to that, resistors can have corrosion on them like rusted legs that can go inside the package and ruin them, and that's not always visually obvious from the outside. Also, resistors can burn up partially and you won't be able to see it from the outside either.

Just check anything that looks weird and anything close to a heat source like a transistor mounted to a heatsink or smaller resistors that are next to larger power resistors that are meant to get hot


I could not find a replacement for the one bipolar 3.3µF @ 160v cap that lives in the H circuit. They just don't make bipolar caps with that kind of voltage tolerance anymore.

It's possible to create a bipolar cap from two polar caps. Do a google search for the way to do it

It's possible to create a bipolar cap from two polar caps.

A bipolar electrolytic capacitor can also be made by connecting two normal electrolytic capacitors in series, anode to anode or cathode to cathode. (https://en.wikipedia.org/wiki/Electrolytic_capacitor)

What isn't mentioned is that doing it this way should cut the overall capacitance value in half. Some also say it decreases the volt tolerance.
I'm not taking a risk with such a hack.
Do a google search for the way to do it
I use DuckDuckGo and you should too (https://spreadprivacy.com/why-use-duckduckgo-instead-of-google/), if you respect your privacy. Which is already dead (https://youtu.be/LLM5oX0riKY), I guess.

What isn't mentioned is that doing it this way should cut the overall capacitance value in half. Some also say it decreases the volt tolerance.
I'm not taking a risk with such a hack.

You can over provision the voltage handling to avoid any risk, and you up the starting capacitance to reach the target bipolar value. It's also fairly common to parallel a film cap across the electrolytics in order to keep the ESR impedance low.

If you do it right, it's not risky.

Also, you can probably just use a film cap instead and be done with it. There are some places in a set that you might not want a film cap because it will cause ringing or uneven brightness, but most places it's fine

It used to be many years ago that film caps were simply not available in higher capacitances as electrolytics were, and they tended to be more expensive, so they didn't use them. Nowadays, you can get them up into normal value ranges pretty high; although the very high ones are still pretty expensive

R804 has got to go.
Well, while replacing R804 today it turns out the in-circuit resistance reading was incorrect. It was always 12kΩ even with the paint bands falling off!! I replaced C1603 and C1604 but there's no difference in behavior. I have replacements for all the small value bipolar caps but something tells me that won't fix the H sync either.

The H lock fails began post-recap, picture was fine before it. First thing I did after the recap was run with a 100W or 200W lightbulb in the +B circuit. I removed the bulb when strange behavior occurred (no picture, audio still running). So either the lightbulb caused damage, or something is different after the recap.
Not to mention the other complications that appeared when reflowing solder joints for the PSU, H circuit and chroma zone.

Here are extra pages from the Sams'.
https://i.ibb.co/pQXRFXV/Panasonic-monitor-002.jpg (https://ibb.co/dtKLYKC)
https://i.ibb.co/s6MdQw1/Panasonic-monitor-006.jpg (https://ibb.co/P9fv4hW)
https://i.ibb.co/jWQLnXc/Panasonic-monitor-007.jpg (https://ibb.co/fnyCjwh)
https://i.ibb.co/Y8QNGGt/Panasonic-monitor-008.jpg (https://ibb.co/92gpjjq)
https://i.ibb.co/FqkyX1k/Panasonic-monitor-009.jpg (https://ibb.co/LhDcryD)
https://i.ibb.co/QNvXfpg/Panasonic-monitor-010.jpg (https://ibb.co/wWhYRBk)
https://i.ibb.co/VWzBxkX/Panasonic-monitor-011.jpg (https://ibb.co/vxTzhM2)
https://i.ibb.co/3sKBV02/Panasonic-monitor.jpg (https://ibb.co/RS8ztCf)

I replaced some small value bipolar caps, and the one near the horizontal driver transformer. Same issue. (didn't replace any resistors as I haven't found more bad ones YET) https://youtu.be/P8dgQ33JAhQ

Although it's hard to see in the video, the picture shrinks (and sides curve inwards) slightly as it warms up. So I think there's still an HV/power supply issue.

Oh, and I recapped the "channel selector" board & audio circuit (couldn't replace a few caps though). Now there is no sound, but I can still hear the amp working (so in other words it acts as if I don't have audio plugged in).

Q554 emitter is at 12v! What is triggering the H osc disable circuit?

At this point, I wouldn't be surprised if there wasn't a hard-to-see break in the PCB or something. PCBs can get brittle with age, and a drop or a jostle (like from being taking out of storage and put on the side of the road) can cause little fractures

Usually the best way to stumble upon such an issue is by following voltages. if you get the right voltage at one end of a supply, and then you follow it along the trace to components, you will often find a break in the PCB by finding it not where it is supposed to be

It's kind of like doing a Sudoku and figuring out a row or box by omission

Of course it's not for sure, but it's one thing you could do if you're feeling stuck (follow all voltages from their supplies)

The Hor lock issues could be the Hor Frequency adjustment. You usually put a small white box up, and then short a transistor in the Hor circuit and adjust the freq pot until it stands still or as close as you can get to it. Usually in older TVs I've never been able to dial it in perfect, it always drifts a little (in the adjustment phase, it always works fine after reconnecting the circuit)

Edit: actually, I just read your manual and apparently you don't need to short anything, there is an adjustment for HSYNC, R505 which can be tweaked without any other procedure

Limiting the TV power with a bulb can have weird effects on voltages inside the set. I know I've seen issues with not having enough juice to start the Hor oscillator, which can throw off voltages in that circuit. It was a tube TV though, so I don't know if the same thing can happen in a solid state set as I've never tried it

Also, probe the 3.58MHz crystal in the Hor circuit to make sure it's outputting the correct frequency. If the crystal is pooched it will mess a whole slew of things up

Also, probe the 3.58MHz crystal in the Hor circuit to make sure it's outputting the correct frequency. If the crystal is pooched it will mess a whole slew of things up
I don't have a scope or frequency counter :(

As I said, there's 12v on Q554's emitter which means the H osc. disabling circuit is activated (which is what's deliberately throwing H sync off as a "safety feature"). I don't know why it's activating though. Could be excess HV??

I don't have a scope or frequency counter :(

As I said, there's 12v on Q554's emitter which means the H osc. disabling circuit is activated (which is what's deliberately throwing H sync off as a "safety feature"). I don't know why it's activating though. Could be excess HV??

Idk for absolute certainty, but I would suspect that using the bulb or a Variac could prevent the Hor oscillator from starting, which could in turn throw off voltages inside the set, or maybe do something weird with the "disabling circuit," especially if there's still something else wrong

There are some low cost scope options for someone on a budget that will at least give you some feedback. For around $100 you can get a little handheld battery powered one that will be high enough to capture the bandwidth of a crystal. Check out this video https://www.youtube.com/watch?v=iG0-0R9qYWU
The cheapest one only goes up to 200kHz, so I would probably avoid it.

Idk for absolute certainty, but I would suspect that using the bulb or a Variac could prevent the Hor oscillator from starting, which could in turn throw off voltages inside the set, or maybe do something weird with the "disabling circuit," especially if there's still something else wrong
Uhhh I don't test with the bulb anymore. The disabling circuit still activates without one present.
Please, pay more attention to the thread.

There are some low cost scope options for someone on a budget that will at least give you some feedback. For around $100 you can get a little handheld battery powered one that will be high enough to capture the bandwidth of a crystal.

Yeah, I don't exactly feel like blowing a hundie just to debunk ONE crystal, especially when a replacement crystal probably costs less than the oscilloscope itself!

I measured various PSU voltages, just to be sure:
19.77v line = 18.77v
12.10v(A) line = 12.40v
12.10v(B) line = 12.36v
12.09v(A) line = 12.39v
160v line = 155v
11.60v line = 9.80v (measured from C559 instead of L351 because I didn't bother playing this game of Where's Waldo long enough)

Yeah, I don't exactly feel like blowing a hundie just to debunk ONE crystal, especially when a replacement crystal probably costs less than the oscilloscope itself!

I measured various PSU voltages, just to be sure:
19.77v line = 18.77v
12.10v(A) line = 12.40v
12.10v(B) line = 12.36v
12.09v(A) line = 12.39v
160v line = 155v
11.60v line = 9.80v (measured from C559 instead of L351 because I didn't bother playing this game of Where's Waldo long enough)

Looks good enough to me. As I mentioned earlier, you could also trace the voltages around the board. If there's a break in the PCB somewhere, that's usually a good way to find it because voltages are stable and predictable. Also, since you don't have a scope, you won't be able to check the various waveform that the Sam's calls out. Which, incidentally, is also a good reason to have at least a basic scope. You can look at all of those little black windows in the Sam's to make sure they look right.

If you plan on doing this kind of thing any more than this one set, a scope is a pretty core tool in electronics troubleshooting

As I mentioned earlier, you could also trace the voltages around the board. If there's a break in the PCB somewhere, that's usually a good way to find it
I'd likely need a fuller picture of the Sams' for that. Right now, I only have about a dozen pages out of 30. And I seriously doubt the board is broken, as the picture was perfect pre-recap. If it were fractured, how the flinkerjub would I begin repairing such a fault?

Also, since you don't have a scope, you won't be able to check the various waveform that the Sam's calls out. Which, incidentally, is also a good reason to have at least a basic scope. You can look at all of those little black windows in the Sam's to make sure they look right.
And I sure wonder how'd you go about fixing a bad waveform. Actually, I think it might be worth it to buy the full Sams' for this TV, considering all the problems we're wading through.

If you plan on doing this kind of thing any more than this one set, a scope is a pretty core tool in electronics troubleshooting
This is a one-time ordeal. I hope.

About the H disable circuit - I'm seriously stumped as to why it's being activated. Hopefully our lord and savior Sams' shall yield thy answers...

I seriously doubt the board is broken, as the picture was perfect pre-recap.


You clearly had issues or you wouldn't have been recapping anything. But even so, problems can get worse or become less intermittent when you work on thing or have it on for longer. Just moving stuff around and (more importantly) heating things up has a tendency to make problems come out.


If it were fractured, how the flinkerjub would I begin repairing such a fault?


You would bridge over the traces with wire, or solder bodge wires to restore continuity to the broken trace(s).

I'm not suggesting that it's the most likely problem, but it's a possible problem that should be fairly easy to check out with a multimeter.


And I sure wonder how'd you go about fixing a bad waveform. Actually, I think it might be worth it to buy the full Sams' for this TV, considering all the problems we're wading through.


You would take the bad waveform as evidence that the circuit is pooched in that particular area of the board and start testing components connected to it. Some people are good enough to know what is likely wrong just from that, but I would have to just test stuff mostly. If the waveform originates from an IC and not a group of discrete components, it might be a sign of a bad IC, and it is usually possible to lift things out of the circuit and test the output of the IC removed from any possible shorts or loads and see if it's good or not.



About the H disable circuit - I'm seriously stumped as to why it's being activated. Hopefully our lord and savior Sams' shall yield thy answers...

I wouldn't know. Hopefully one of these other oldbies can't point you right. My level of troubleshooting is "okay," and I can generally figure stuff out if it's right in front of my face and I'm working on it.

You clearly had issues or you wouldn't have been recapping
I recapped because HOTs kept blowing out. Did you see this? (https://www.videokarma.org/showpost.php?p=3256681&postcount=48)

I read about H osc. disabling circuits in other Panasonic TVs. It pumps up H frequency to eliminate X-Ray risk if HV is found to be above spec. Which might explain why the picture is so bright & shrinks sometimes. But most other sets from other brands simply shut down if HV is too high.
I can't test the HV without a high voltage meter though.

133 volts may be OK but you need to see if it changes. Use a variac
or go from zero brightness to full brite. It must stay the same.

Well I did some testing tonight and found the +B voltage floating around. It was up to 125v with a dark picture but lowers to 120v when bright. +B control resistor DOESN'T work sometimes. Sometimes it goes back to 130v and that's when the H osc. disable circuit gets triggered. I think the low voltage regulator is crapping out! https://youtu.be/OqzFIbvbYJQ

The lack of color & white horizontal dots seriously concern me. Honestly, I'm almost at my wits end with all these failures!
Considering just sending this set off to Multi Media Medic in Maryland.

Considering just sending this set off to Multi Media Medic in Maryland.

If I was seeing fluctuating voltages in the B+, I'd probably suspect one of the transistors of being flaky. Sometimes they only behave poorly when under load, and they test okay when you take them out. Usually, that will come out when you use a curve tracer, but not always. And they are pretty expensive

Interesting. I live in Maryland but I didn't know about that guy. I used to always go to a dude in Silver Spring called Danco, but he's semi retired now and he won't always take stuff in if he doesn't want to. Last thing I brought to him he sat on for six months and then said he didn't want to do it lol

Does anybody know why the color is gone & how to fix? You can kind of see it but just barely.

In an attempt to cripple the H disabling circuit I left R539 open, and switched the set on. I've never seen the HOT blow out quicker!
I give up.

https://i.ibb.co/hy5fHTZ/Panasonic-monitor-013.jpg (https://ibb.co/NshSpGm)
https://i.ibb.co/x32y14X/Panasonic-monitor-012.jpg (https://ibb.co/9GpJbMc)

Interesting. I live in Maryland but I didn't know about that guy.
Well I tried calling this Multi Media Medic man today and he didn't pick up. Left him a voicemail but I doubt I'll get anything back.

Please, enlighten me to any other repair shops or techs in Maryland or Virginia. I cannot bring myself to work on this set anymore. If anything, I can sell it for parts on eBay or something...

MUSTS HAVES !
Power supply must be 130 VDC under both zero beam current or max
( full normal brite ) beam current. & varying line voltage. If not suspect
Q801.

Too bright. REPLACE C559 no matter what, its very common on ALL
brands of TV's, Its in the top ten TV problems. Lots of different symptoms too !

G2 must be about @ 300 VDC too high = too bright.

CRT cathodes need to be @100 VDC. Too low too bright & visa versa.

Blows HOT. Be sure its running cool. If not it WILL give up soon.

NOTES : The FBT's in this era of Pannys / Quasars were trouble. Usually
windings shorted & it cooked, crackled, smoked then blew the HOT.
It ended the TV often. On yours it MAY be it has a bad triple / divider
section.
Last keep in mind to do things right you need: a variac / isolation transformer(S). quality meter & good 100 + Mhz scope with 1 KV probes. Anything less is pushing it. Just think of the $ in blown parts you will save
if you do more sets.

73 Zeno:smoke:
LFOD !

Too bright. REPLACE C559 no matter what, its very common on ALL
brands of TV's, Its in the top ten TV problems. Lots of different symptoms too !

I've already done a near-full recap.

Does anybody know why the color is gone & how to fix? You can kind of see it but just barely.

To have a good color pix you NEED a good B&W pix first. Ignore the
color & audio until you have a good B&W set.
The set had ONE part or PC con fail then maybe some other damage, a chain reaction. There is an order to it. Always follow it, any set.
1) power supply
2) hoz osc & drive.
3) hoz out & HV
4) vert sweep

At that point you should have a B&W raster & you can clean up any
other problems. Trust me on that, I fixed tens of thousands of TV's
in my time.

Zeno:smoke:

This is my first CRT repair and I think it's gone over my head by this point. The set has multiple, intrinsic issues. I need another tech with EXPERIENCE to look @ this.

I found another place in Maryland that specializes in Panasonic among a few other brands. https://fnpsites.net/shipley/
Sent out a message with their contact form, never got anything back. I should try calling.

Please, enlighten me to any other repair shops or techs in Maryland or Virginia. I cannot bring myself to work on this set anymore.

Honestly, no. I don't know of anyone I can fully recommend. Danco is a great tech, and he won't rip you off, but he is retired and doesn't care about taking jobs unless they are interesting to him, and he has told me on numerous occasions that he especially doesn't like taking in jobs that other people have been messing with.

There's no one I'm aware of in Maryland that will take in a CRT and can be trusted other than him (if he will do it), and I don't think he's too likely to touch yours, and if he did you would be paying out the nose for it because he charges hourly and his time is valuable.

There used to be a LOT of guys in the area who would do it, but they all retired and/or died like 20 years ago. Danco was a late arrival, and then he made most of his living handling all the audio/visual equipment for the National Zoo, and doing big important restoration jobs for museums and stuff like that, so he could afford to keep the small neighborhood shop running.

I think you're going to have to look in Northern VA, there's a much better chance of finding someone over there.

But seriously, this particular TV you are working on isn't worth what someone competent is going to charge you. You could easily be looking at over $100/hour for that kind of thing, and it's a basket case.

My advice is to keep cracking at it, or let it go. And that doesn't have to mean getting rid of it; you can mothball it and get back to it after you have more experience.

Also, you might want to give some thought to getting some better equipment if you want to mess with this stuff more. At the very minimum, an isolation transformer is really important as a safety precaution. Without one, your line leads are connected directly to the grid on the neutral

this particular TV you are working on isn't worth what someone competent is going to charge you. You could easily be looking at over $100/hour for that kind of thing, and it's a basket case.
I think it's worth it. Almost nobody has these CT-1310s anymore (Well, my neighbor did, until I showed up a month ago). We'll just have to see what Shipley's says. After all, they appear to have rave reviews and are still in service.

If I must continue working on this set, the way forward would probably be replacing transistors and diodes. After all, the HOT is a big transistor & was blown when I first got this set (which is why it'd been thrown out).

So what makes this set so valuable?

I just called up a bunch of shops and techs in Maryland and nobody in the area can or will work on my Panasonic set. I guess I'm still on my own here!
So, how should I test, order, and replace bad diodes/transistors in the PSU/Horizontal circuits? Those are the only problem I can think of.

[QUOTE=luRaichu;3257145]I just called up a bunch of shops and techs in Maryland and nobody in the area can or will work on my Panasonic set.

This doesn't surprise me really, the number of "TV-Radio" repair shops remaining are but a small fraction of what they were a quarter century ago. Most of those techs are retired or have become silent and the few that are around know little to nothing of the legacy technology. I grew up in TV shops having them in the extended family, both had closed up by the mid-90's because the business dried up.

So what to do about your ailing Panasonic Color Pilot:
If it was me I'd go back over my work again after a short break, say a week or more to get it out of my head.
Starting over with in-circuit checks of transistors knowing the junction is about 0.75 volts, I use a Fluke model 77 DVM that I've had since the mid-80's and it has a real diode check function that shows the actual junction conduction voltage. Okay so the semiconductors all show the correct forward drop in their respective directions I then move on to capacitors. You said that you have replaced a majority of electrolytics, what did you use? This is very important as the vast majority of chinesiums are bad right out of the box. When I say bad I mean internal current leakages and high ESR values. More often than not I will use salvaged capacitors out of the last generation surround receivers that had worked but replaced for an "upgrade" and these salvaged units are performing well. One of my present 16:9 monitors is a Panasonic CT34WX54 widescreen CRT that is presently running salvaged electrolytics along with ALL of my Sony PVM-5300 triple monitors I use for production work. 1984 vintage take-outs from the local FOX affiliate with millions of hours they got recapped with salvaged caps and work as they should. Have you gone over the top of the board and actually verified each capacitor is the proper value according to the schematic AND the polarity is correct?
Okay so we "think" the electrolytics are good being name brand parts like Nichicon then I'd move into the various supply voltages following the schematic. With the horizontal transistor blown I'd remove it from the circuit and sub in a 40-watt incandescent lightbulb between the emitter & collector to load the main part of the power supply, no you won't have any sweep but this is not important at the moment... an oscilloscope however would be most helpful and the reason for this is even without the HOT in place there should still be drive available on the collector of Q501 unless the failsafe has an issue. Without horizontal pulses coming into the failsafe it shouldn't trigger a shutdown. How about voltages? We don't need exact numbers here, +/-5% is a good working margin. That being said what are the voltages going on the various circuitrace flags listed on the schematic? If they're within the spec tolerance how about at the various collectors of transistors or the VCC point of IC301? I've been trying to follow along the schematic you posted the image of but the hosting site is a pain and I can't see the whole thing.

The problem here unfortunately is a lot of variables have been added and it's become a circle of tail chasing with the only solid result being shorted horizontal output transistors and frustration. Replacing capacitors was a necessity, you pulled one that was missing a lead that had corroded away however without the necessary test equipment you're still trouble shooting from the hip.
Those flybacks have been known to short & fail, the ones I've experienced won't even run long enough to light up the screen but that's not to say it couldn't while eating expensive transistors along the way.

I've been going through all of your posts trying to put together a summary of what has been accomplished to this point. Electrolytics replaced, resistors tested and a complete resolder. This is the one that I'd focus on first, with a magnifying glass and lots of time. All it takes is a bridged pair of pins on an IC or between two close spaced leads to throw everything into a tailspin. Have you carefully done a visual on the board and I mean out of the chassis? Don't like the smell of flux? Sorry but it's a fact of electronics repair and you will have to deal with it. Personally I'd pull the board completely and do a de-flux using the fuel additive "Purex99" in the red bottle, that is 99% pure isopropyl alcohol and that will take ALL the flux off with a little scrubbing with an old toothbrush. From there I would be looking at every connection following the traces around and giving attention to the closely spaced leads for any sign of a bridge. This can take some time... a lot of time. I'm also seeing a lot of frustration and impatience, I pick up on these things. It's this frustration and impatience that makes a big pile of smoked parts.
What I can't do is fix this over the internet despite my past experience with them, until I actually get my hands in something and a feel for what's going on all the explaining in the world is not going to help, this is why I say to go back on all of your work starting with fresh eyes after taking some time away from it.

Options and I'm being serious here. One is you could keep at it and take things step-by-step. Two is finding a someone willing to work on the set but that sorta defeats the prupose doesn't it? I mean you fixed a McIntosh right? Three is you could box it up and donate it to me so I can fix it and add it to my collection saving the remaining horizontal output transistors of the world from certain destruction. I'd even pay the shipping.

I then move on to capacitors. You said that you have replaced a majority of electrolytics, what did you use? This is very important as the vast majority of chinesiums are bad right out of the box.
I used mostly Würth Elektronik & a few Nichicon caps. I would never trust the cheaper brands like "Elite".

Have you gone over the top of the board and actually verified each capacitor is the proper value according to the schematic AND the polarity is correct?
I couldn't cross-reference with the Sams' as I don't have all pages; but I've checked and every new cap installed is the exact same capacitance, same voltage rating or higher as it's predeccessor. Polarity is easy because most if not all caps on the main board have their negative side facing right.

Okay so we "think" the electrolytics are good being name brand parts like Nichicon then I'd move into the various supply voltages following the schematic. With the horizontal transistor blown I'd remove it from the circuit and sub in a 40-watt incandescent lightbulb between the emitter & collector to load the main part of the power supply, no you won't have any sweep but this is not important at the moment... an oscilloscope however would be most helpful and the reason for this is even without the HOT in place there should still be drive available on the collector of Q501 unless the failsafe has an issue. Without horizontal pulses coming into the failsafe it shouldn't trigger a shutdown. How about voltages? We don't need exact numbers here, +/-5% is a good working margin.
As you might have seen, I measured and re-measured the PSU voltages prior to the +B regulator taking a nose dive. Everything seemed up to spec then.
Also, I agree, an oscilloscope would be useful at this point. Perhaps I'll look into getting one. But I think the 100 watt lightbulb in the post-recap +B circuit overloaded the PSU or something else, and caused damage. That's why I somewhat suspect burnt resistors, diodes, and transistors as they may have had their power rating exceeded by the bulb's current draw.

I tried running with a much smaller 15 watt bulb in place of the +B fuse but the set wouldn't power up this way. Only a feeble whine. After I removed the bulb, that's when +B started floating around low.

That being said what are the voltages going on the various circuitrace flags listed on the schematic? If they're within the spec tolerance how about at the various collectors of transistors or the VCC point of IC301?
Good call. I will check this.

I've been trying to follow along the schematic you posted the image of but the hosting site is a pain and I can't see the whole thing.
You can download them from the hosting site and magnify with your image viewer of choice. If not I can put the schematics up on the Internet Archive and you may see them better there.

Don't like the smell of flux? Sorry but it's a fact of electronics repair and you will have to deal with it. Personally I'd pull the board completely and do a de-flux using the fuel additive "Purex99" in the red bottle, that is 99% pure isopropyl alcohol and that will take ALL the flux off with a little scrubbing with an old toothbrush.
It's only the OLD flux that really smells like shit. I've always been fine with it though, but my neighbors sure aren't.
Couldn't you use the 90% alcohol they sell at drug stores?

I mean you fixed a McIntosh right?
Yes, but all that'd brought it back from the dead was a complete and utter recap. Despite this I couldn't save the floppy drive & ye olde spinny hard drive soon died from goopy head bumpers.
Also this was one of the cheapo, "pizza box" form factor Macs. They weren't the early compact ones with a 9" CRT built-in, you had to source your own monitor for these.

An oscilloscope yes, but also a an isolation transformer. That will greatly reduce the chance of a fatal accident if you touch the wrong thing

this is just about the cheapest scope you could get any use out of. (https://www.amazon.com/ZOTEK-Automotive-Oscilloscope-Multimeter-Tester%E3%80%81Voltage/dp/B0C3D1KVPB/ref=sr_1_14?dib=eyJ2IjoiMSJ9.B2WJ4g2LoIUy-vpg7jrnjV_J1yzy66F4sSFdpkGgm-H6on1YGaLDc4j_ZkW61ckqG7N2tCIyUTj3F6ehyBQkbz2mUKuz oaN7N7DlWuhUYwcfgi_RiXgnoZDx8R273HnTKJp_H-UqHOzSGNjpxWiCHq7BiBQxOXRCElTaY18F5j-6pBzepTGJgGaVLMsovc--l94pJRtWjIG5lkwpfercgte3p9fTNtk4iPWsbTyAv3Y.VH-4TJDcTSoqayr-zJV6HKPUukgOFeD0wjs-kIWd22Y&dib_tag=se&keywords=oscilloscope&qid=1715210996&sr=8-14) You still can't do high voltage without differential probes, but you would need to buy those separately with more expensive scopes as well

also, get yourself one of these types of devices (https://www.ebay.com/itm/375292627205?itmmeta=01HXD921CYQ10JVK43YQ0FX5NW&hash=item57612f0905:g:bP0AAOSw12Vl5olp&itmprp=enc%3AAQAJAAAA4Ahf13fXDiI3N%2BlztE06bCZQryv WyW8e1yNgXTUcynhZmw5rplV0vw2pjOrIyM3alkTWVhCkDvKEw ny2Wh5UAWvDIB7OVFGUDFewkFrbqLkIdeEuXf6OKmC0Fom3yI9 eu%2B3FRiXBC%2FPDSRSop1J1fHjZeeDC%2FrIIOmnLNLivziS aszMnKHwCo7BucqfJOuDL5a2%2Ffxa0KbAScW0g1KYKcdD50Ui zrFEM0EfGfWxrjLqpCj2AeVMZ5ORaXK5DkjfUNRSc0lV%2B6XM pQ%2BhxlZxZxERcIHU4vA5puz9bTrX3gwpu%7Ctkp%3ABFBM0p aIqetj) to do a quick check on diodes and transistors. It's not completely foolproof, but I find they generally don't lie, and they will almost certainly tell you if a transistor is still showing as one or not. Capacitance is also fairly accurate up to a certain point. I think they start to get so-so around 2200uf and up

I'm not specifically endorsing either of these two devices or sellers; there are many versions of them on amazon and ebay, and they are all pretty much the same thing AFAIK. Just read feedback and stuff and find a good deal on a good one

Can't power on the set yet so here are pictures of the mainboard I took today. Feel free to pour over them, I cannot see anything wrong myself.
To get the full-resolution photos please download from imgbb.
https://i.ibb.co/1spCD73/IMG-6397.jpg (https://ibb.co/6vpK3r2)
https://i.ibb.co/XDqNTff/IMG-6398.jpg (https://ibb.co/W0Lq1NN)
Note: C605 appears bridged in the first photo, but it is not.
When doing the first solder reflow, I noticed C751 was bridged. I don't know how long it was bridged for. Since then, C751 has been replaced but to no improvement.
The horizontal driver section may've been pooched by the C751 short, now that I think of it. Should check waveforms.

Can't power on the set yet so here are pictures of the mainboard I took today. Feel free to pour over them, I cannot see anything wrong myself.

Doesn't appear to be broken to me. A couple of notes.

1) that resistor on the back of the PCB is somewhat sus. i've had issues with those plastic package resistors before. maybe it's fine, but could be worth testing them if there are any others on the front side. the one bodged onto the back is unlikely to make a huge difference anyway, but if there's one, many there's others

2) there's one spot towards the bottom that i don't understand. it looks like missing solder on a connector or something, but perhaps that is supposed to be that way?

this:

https://i.imgur.com/iqNOeJA.png

I grew up in TV shops having them in the extended family, both had closed up by the mid-90's because the business dried up.


Did they miss the renaissance or what?

In the mid 90s, I made a fortune servicing RPTVs and even tons of CRT TVs like the RCA CTC17X series as I was an ASC for Thomson. I was doing between 5-10 CTC 175/6/7s a day. I knew them so well I didn't even look at them before calling the customer to give them an estimate (I pretty much flat rated them based on screen size). Most were corrupt eeproms from bad grounds on the tuner shield, horiz output, and regulator output heatsinks. A few flys here and there but the flybacks were pretty cheap.

On rear projection TVs, most problems with Japanese brands were convergence related and I used to buy STK modules a hundred at a shot.

The RCA rear projectors didn't have convergence problems (all discrete components) but the guts were built in a crate - two brackets and two unplug harness and the box was out of the TV and in the truck in 5 minutes. Most RCA projection problems were smps rebuilds or HV splitter boxes.

Good days.

John

At that time I wasn't interested in lugging the brutes around and they were looking to retire, I remember hauling a few of those big 30+ inch CRT's to the bench but never got into the RPTV's. I miss the days of the EZ triplers and sagging 3A3 heaters that took out the flyback.

Getting back to the Panasonic I see so many suspect connections I don't know where to start but D551 anode is just as good as any. First soldering takes a lot more than globbing it on the connections and hoping it conducts, they need to be heated until the solder flows. Those connections on the flyback are not up to par by any means. I see the majority of solder connections have not been touched and they are all suspect until addressed. Soldering is a skill that comes with years of practice, not something you can learn from a book. Honestly I think you bit off more than you can chew with this one.

Originally Posted by luRaichu
Can't power on the set yet so here are pictures of the mainboard I took today. Feel free to pour over them, I cannot see anything wrong myself.

And this is what separates the experienced. just a quick glance I see a halo around the anode of D551, the posts around the DY terminals esp #3 don't look very good. TPB4 looks to be shorting across to the adjacent trace for TPB3 just above R603. All of the connections around the flyback pins need to be reflowed and when I say this I mean heated until the entire solder connection melts and flows around the pin, simply touching the glob is not going to cut it and with all that has been done so far I wouldn't be surprised to find blown semiconductors. You're going to need a lot more luck to get this one working right again.

At that time I wasn't interested in lugging the brutes around and they were looking to retire, I remember hauling a few of those big 30+ inch CRT's to the bench but never got into the RPTV's. I miss the days of the EZ triplers and sagging 3A3 heaters that took out the flyback.



Man, triplers were great - they'd generally arc and burn through and people were so happy when the price to repair the TV was half of what they were afraid of what it would be because of the acrid smoke they'd belch..

As an ASC we had to have a test jig, so I didn't do much lugging. I also cheated a bit - if we had a big tube Sony that was dead, I'd just grab the chassis even though I didn't have any test jig adapters for them and just use a scrapped yoke and HV probe. I kept a bunch of yokes on the shelf for that reason. When I got the power and HV repaired as indicated by the HV probe, I'd just return the chassis.

John

TPB4 looks to be shorting across to the adjacent trace for TPB3 just above R603.

No, it is not. See the 2nd pic.

Also, I guess it wouldn't hurt to work on the flyback's pads a bit more, and the other things you'd mentioned too...

Man, triplers were great - they'd generally arc and burn through and people were so happy when the price to repair the TV was half of what they were afraid of what it would be because of the acrid smoke they'd belch..

As an ASC we had to have a test jig, so I didn't do much lugging. I also cheated a bit - if we had a big tube Sony that was dead, I'd just grab the chassis even though I didn't have any test jig adapters for them and just use a scrapped yoke and HV probe. I kept a bunch of yokes on the shelf for that reason. When I got the power and HV repaired as indicated by the HV probe, I'd just return the chassis.

John

We didn't cheat so much, I was a 20-something who was bigger than his britches and would literally pick those big tube sets up solo and gracefully load them in the van, now at 55 I'm feeling every one of those on every bump I hit on the road... not so graceful today.

Set was disposed of against my will. Sorry guys.

Was it rare?

Sort of. Rare, but not especially desirable. I think they probably made a decent number of them, but they were mostly installed in motels and the like, and they got used a lot and thrown out when they died.

I honestly wouldn't feel too terrible about it; there are a lot of Panny's out there that people like a lot more.

If you want to see some cool TVs from the general era being worked on by a good hobbyist, check out this youtube channel: https://www.youtube.com/@ResurrectionRetro/videos

He's definitely got a few Panasonic TVs in there. It will give you an idea about what you can sometimes expect them to be like when they are working

Make sure your stuff can't get involuntarily tossed before getting more stuff. If your parents or roommates did it chew them out HARD. If you stored it someplace vulnerable and public switch to keeping it someplace private.

I'm big on boundaries so anyone getting enthusiastic with a garbage can knows to stay in their lane.

Eh, it was free anyways and the flyback MAY have been bad. I’m looking at the Commodore 1701, but those sets are $$$

Gotta ask what your goal is with the monitor?

Yeah, the intended purpose of the monitor is going to drive the kind you want to have. But honestly, you're probably best off just looking for something in good condition locally. Check out FB marketplace or Craigslist

I want a 10-13" NTSC monitor with decent resolution for experimenting, retro gaming and watching my VHS/Betamax tapes. Curved screen because flat is BORING.

As for Facebook, they're evil and I've only used them twice to contact people I couldn't find anywhere else. I don't wanna visit their Marketplace, at least not without a slew of privacy plugins installed.
But I haven't checked Craigslist. Good idea.

they also pop up in thrift stores sometimes, but less so nowadays

you can also look on ebay and try to find something local that you can pick up. i wouldn't have anything shipped if you can avoid it because there's a fairly high damage rate with shipping CRTs