1960s vintage 9" GE B & W Portable TV has no Picture - Page 5 - Videokarma.org TV - Video

***Eric H*** · #61 10-20-2015, 12:01 AM

I probably have the Sams for it somewhere around here, If I can find it I'll scan it for you, I can send a copy to the ETF too so it'll be available in the future.

***Eric H*** · #62 10-20-2015, 01:12 AM

Here's a link to the Schematic, Right click and "Save As"

http://vintagetvsets.com/schem/359-7%209T001.pdf

Captainclock · #63 10-20-2015, 02:21 AM

Quote:

Originally Posted by Eric H

Here's a link to the Schematic, Right click and "Save As"

http://vintagetvsets.com/schem/359-7%209T001.pdf

Thanks very much for the copy of the sams, I have now figured out that the reason why I'm having issues with the bottom of the picture being folded over on itself and not have very good vertical linearity is because possibly the 10C8 Vertical Output tube might be either very weak or bad, there are two 10C8 tubes in this TV the other one of which goes to the Audio Amp stage, which works fine so I might try substituting the Audio Amp stage tube for the vertical output tube and see if that makes a difference with the vertical linearity in the picture if it does then I know that the 10C8 tube is what's causing my problems and not necessarily capacitors (although I'll probably replace the capacitors anyways since I got them just to be on the safe side).

EDIT: Iwas able to swap the Audio Output tube and the Vertical output tubes which are both 10C8 tubes and I was able to almost fill the entire screen except for the very top of the screen and that was with the height and vertical linearity controls jacked up about 3/4 of the way up.
So it seems that now I know that the TV's issue is a combination of a weak 10C8 tube and some bad capacitors in the vertical section. Which like I said I had already ordered some new capacitors for the TV and should be getting them by Thursday.

Captainclock · #64 10-22-2015, 01:13 PM

Ok So I got my capacitors today and I just finished replacing the old capacitors and I went to test the TV out and for some reason the TV is giving me a very poor picture that's nothing but a small line in the middle of the screen that rotates in a circle (kind of like an analog tape counter except a little faster) and the screen goes completely dark at either end of the brightness and contrast controls but is visible in the middle of the controls, I also have to mention that a couple of traces lifted when I removed the old capacitors (the traces that the capacitors soldered into lifted but didn't break). I have a photo of what the TV is currently doing, that I've posted below.

Electronic M · #65 10-22-2015, 03:44 PM

Looks like your B+ is low. Focus on the PS lytics.

Captainclock · #66 10-22-2015, 04:54 PM

Quote:

Originally Posted by Electronic M

Looks like your B+ is low. Focus on the PS lytics.

Ok but why would of the power supply caps suddenly gone out when they were working fine for the most part before I recapped the TV? Because before the TV was competely filled except the bottom part which was folded up on itself but now its not even completely filled and the image on the screen rolls around like a can on the ground or like a cement mixer truck, and the brightness and contrast controls are being screwy.

Electronic M · #67 10-22-2015, 05:01 PM

You did already recap the power supply?....I assumed you had not. It still looks like low B+ to me. Shrunken H and V (to that extent) usually indicate low B+. Low B+ can be caused by things other than lytics too....Check your B+ against the schematic.

The rolling is probably synch....Which also will go screwy if B+ dips too low.....A bad PS will usually affect (not always noticably) most to all other circuits.

Findm-Keepm · #68 10-22-2015, 06:24 PM

Quote:

Originally Posted by Electronic M

It still looks like low B+ to me. Shrunken H and V (to that extent) usually indicate low B+. Low B+ can be caused by things other than lytics too....Check your B+ against the schematic.

The rolling is probably synch....Which also will go screwy if B+ dips too low.....A bad PS will usually affect (not always noticably) most to all other circuits.

I agree 100% - looks like an open input filter in the B+/doubler.

B+ can cap(s) (100-160uF typical) need replacing.

Captainclock · #69 10-22-2015, 10:41 PM

There's two power supply caps in this TV Which one should I go after? There's one that's at the top of the chassis next to the tuner module that's a 300 MFD 150 Volt Electrolytic can cap that goes to the yoke of the picture tube, I'm assuming this is the one you're referring to that's screwing things up?

There's also one on the bottom that's a 60 MFD 300 Volt and 200 MFD 150 Volt multisection can that I'm assuming also might be causing some issues?

would one be able to get capacitors of these ratings over at places like AES? Because these voltage and microfarad ratings are a lot higher than the ones most of your regular tube radios or guitar amps use.

EDIT: This power supply in this TV is going to be a problem to recap, because I was just looking over at mouser and they didn't have any capacitors of the values that I need for this TV, I also looked at AES and they had 2 of the 3 capacitors I needed but the third one which is apparently from what you guys were saying is the most critical one is the one they didn't have which was the 300 MFD 150 Volts (which I realize that now a days its going to be 160 volts but they still only went up to 220 MFD and that was their cut off). Apparently Mouser did have the capacitors in the values I needed but they wanted betweem $15 and $20 for them and I don't have that kind of money to fork over for those capacitors.

Electronic M · #70 10-22-2015, 11:41 PM

300 is part of the antiquated parts number system. Get a 330uF*, and if they don't have 160V, then look for 200V and 250V (higher voltage rating don't hurt). Some Tivo boxes had 330uF 200V caps in them so they have to be offering that value at 160V or higher for a better price. (EDIT: don't be too picky about brand or physical size/packaging either)

* 10% difference from original capacitance value is WELL within tolerance of the original so it will be fine.

Captainclock · #71 10-23-2015, 12:04 AM

Quote:

Originally Posted by Electronic M

300 is part of the antiquated parts number system. Get a 330uF*, and if they don't have 160V, then look for 200V and 250V (higher voltage rating don't hurt). Some Tivo boxes had 330uF 200V caps in them so they have to be offering that value at 160V or higher for a better price. (EDIT: don't be too picky about brand or physical size/packaging either)

* 10% difference from original capacitance value is WELL within tolerance of the original so it will be fine.

Well I was looking under the panasonics, nichicons, united chemicons, cornel dubiliers and vishay/spragues and only vishay/sprague had the values I needed no one else carried them for some reason or another.

but I'll look again under the 330 MFD values and the 200 and 250 Volt caps.

EDIT: I adjusted the search parameters over at Mouser for the more modern capacitor ratings and it came back with results so apparently what I'll need to order are:

68 MFD 350 V
330 MFD 160 Volts
220 MFD 160 Volts

So which brand do you suggest that I go with? Nichicon, Panasonic, or United Chemicon?

Also how would I go about mounting the new capacitors in this TV since the old ones were cans mounted in brackets?

Captainclock · #72 10-23-2015, 09:55 AM

So I think I may have figured out why this TV isn't working right but not sure. I noticed that when I tested my 1V2 H.V. Rectifer tube, that it glowed from the filaments in the tube tester, but when its in circuit in the TV it doesn't glow, and I'm wondering how it is that the TV is able to work properly without the HV Rectifier not glowing or anything, isn't the tube supposed to glow and isn't that how the tube is supposed to function?
And if the tube not glowing in circuit isn't normal then is that maybe the reason why I have low or no B+ voltage in the TV?

MRX37 · #73 10-23-2015, 10:17 AM

Not sure, but if you have contact cleaner, try spraying it in the tube socket, insert and remove the tube a few times, leave it to dry for maybe an hour, plug the tube in, power the set on and see if there's a change.

If not, then check the soldering connections for the socket.

Gregb · #74 10-23-2015, 10:38 AM

I know on my set I had noticed the high voltage lead was all covered with I assume corona dope or something like that. I had measured very low HV and I could hear some arcing but could not see anything. I changed the lead out for some new stuff and the HV came right up to where it was supposed to be and got a nice bright picture.
I also cannot see the filament glow on the 1V2 when in the operation but due to the correct HV I can safely say it is working properly.

Gregb

Captainclock · #75 10-23-2015, 11:24 AM

Quote:

Originally Posted by MRX37

Not sure, but if you have contact cleaner, try spraying it in the tube socket, insert and remove the tube a few times, leave it to dry for maybe an hour, plug the tube in, power the set on and see if there's a change.

If not, then check the soldering connections for the socket.

OK I'll definitely check those two things out.