GE M935AWL restoration

[bandersen]

I was contacted way back in Dec 2023 about some free sets in Winchester Co, New York. A house needed to be cleared out and they weren't sure what to do with these old TVs.

Turns out they had two 60s color roundies and a B&W set. It's my understanding that when they stopped worked, they were just left as pieces of furniture. The original owner passed in the 80s and his wife went to live with a relative. It appears the house was left untouched for decades.





These are the photos I was sent.
I passed on the B&W but made arrangements for the color sets.
Finally, after 10 months of waiting, they have arrived!
I'll focus on the GE in this thread and start another for the RCA.







You can see faint outlines where a sculpture and set top box sat for many years.

[bandersen]

Here's a look inside.
21FJP22 work up after a couple minutes and tests like new.
Yoke, degaussing coil and grounding wire were found disconnected.
All the tubes except for horizontal / HV stuff are original GE date late 1964. All test like new.

6JS6, 3A3C and 6EL6 are RCA branded.






Tried a slow power up and quickly realized the is no B+. Only the filaments are getting power. Likely the circuit breaker is shot.



Trying to pull the chassis right now.

[Yamamaya42]

Originally Posted by bandersen

Here's a look inside.
21FJP22 work up after a couple minutes and tests like new.
Yoke, degaussing coil and grounding wire were found disconnected.
All the tubes except for horizontal / HV stuff are original GE date late 1964. All test like new.

6JS6, 3A3C and 6EL6 are RCA branded.






Tried a slow power up and quickly realized the is no B+. Only the filaments are getting power. Likely the circuit breaker is shot.



Trying to pull the chassis right now.

Also, As you showed in your video, the degaussing coil was unplugged, (plugs into left side of chassis), if this is not plugged in, and the VDR/thermistor combo is bad, it will also kill all power, as it's in line with the breaker, the diode pair seemed rather robust in this set, almost overbuilt, they could go bad, but so far, I have not seen any in the few color sets I have done.

[Yamamaya42]

BTW, those chassis clips are a royal pain to get back in there right and tightened down, it's understandable why they were just left in there like that!

[bandersen]

Originally Posted by Yamamaya42

BTW, those chassis clips are a royal pain to get back in there right and tightened down, it's understandable why they were just left in there like that!

These things?


Looks like there was some trouble with the focus pin. Wire is directly soldered to the CRT pin!


Decided to pull the chassis so I could give it a good look over.
Crazy clean underneath. No obvious signs of any old repairs.




Yes, the circuit breaker is open. There's also a split bumblebee right across the AC line.

I suspect the thermistor or VDR are bad as well since the degaussing coil was disconnected. Oh yeah, I can see a detached lead in the photo!
Are compatible parts even made anymore?

[bandersen]

OK I'm really glad I pulled the chassis now. That terminal in the center of the screen was never soldered!

Are these vintage EM type capacitors plastic film?

[Yamamaya42]

yes, those clips hold rear of the chassis.

I have this weird feeling of Déjà vu!

http://suzaku.live-evil.org/0919202020.jpg

I replaced the entire socket.

http://suzaku.live-evil.org/0928202041a.jpg
And yes, you can still get them.
https://talonelectronics.com has many that will work, not exact but will work, sold in pairs. and they can be found in other places.

[Yamamaya42]

Originally Posted by bandersen

OK I'm really glad I pulled the chassis now. That terminal in the center of the screen was never soldered!

Are these vintage EM type capacitors plastic film?

Looks like C146 & C147 Think they are just standard orange drop film, they should be OK, id they did not burn.

[Electronic M]

I think Chester electronics in Kenosha still stocks thermistor pairs.

[Yamamaya42]

Originally Posted by Electronic M

I think Chester electronics in Kenosha still stocks thermistor pairs.

He's also gonna have to most likely replace the focus diode, and the boost diode, But I forgot which one you suggested to use.

2 in series i believe.

[Electronic M]

Originally Posted by Yamamaya42

He's also gonna have to most likely replace the focus diode, and the boost diode, But I forgot which one you suggested to use.

2 in series i believe.

This. https://www.mouser.com/ProductDetail...BIClpyBQ%3D%3D

You probably can make do with one, but on sets where focus range touches or especially if it exceeds 5KV I tend to use a series pair for added safety.

[Yamamaya42]

Yeah, i was having brightness and focus stability problems so I pulled the chassis for the umpteenth time and replaced diodes, as well as the matched pair of 1.5 meg resistors R137/138 on the 6BK4, and it helped a lot!

[Yamamaya42]

WOW, that circuit breaker seems rather impossible to find at the needed rating for this set.
But the one for the CTC-15 is out there.
https://www.ebay.com/itm/393284894216
It hopefully should work, if you can't find the right one.

[damen]

I don't have a screen shot (maybe someone does) but I think that GE is like the set MR. Ed won and kept moving it from Wilbur's living room to his stall.

[bandersen]

I was able to get the circuit breaker working with some deoxit. I also have a few used but good breakers.

I'm not sure how the rating works for these.
This set pulls about 3 amps, but I see a lot of breakers label "hold 2.1A". What exactly does that mean? Seems like they are undersized?