GE Portacolor II needs help

[joe111671]

I have a Portocolor II with the 10JA chassis that's dead. When I got it, the 0.5 amp fuse for the +135v supply was blown. I replaced it and it blew again. I believe I found the culprit, the .047 1600v cap, C236 is dead shorted. That .0043 isn't shorted, but I don't trust it so it has to go too.

The horiz output transistor, and Y206 & Y208 are not shorted. Anyone familiar with these things that can tell me if it's safe to just replace those two caps and try it out?

Sorry for the poor quality of the schematic, it's the one that's pasted onto the inside of the back cover.

Thanks for any advice.

[JohnCT]

It was far more common for the retrace capacitor to open which would cause excessive HV and take out the horiz output in a flash than to have those caps short. Good thing is that if the cap shorts, it won't hurt the fly or the output.

Replace the two caps and it should work.

John

[zeno]

Yup the 2 white caps. Very common on GE's.
The damper diode & yokes are known to short too.

73 Zeno
LFOD !

[joe111671]

I ordered caps and crossing my fingers. I ordered a .05uF to replace the .047, and a .0033 & .001 that I'll put in parallel to make the .0043.

I hope the "orange dips" are good replacements.

The other thing I didn't mention was the .047 cap across the a/c line blew at some point. It must have made a good pop! I recall reading somewhere that a set will run without it, but could be susceptible to interference or something. Anyway, I'll use this scavenged cap as a replacement unless someone suggests otherwise.

I hope the damper and yoke are still good, I'd love to see this thing work.

[Electronic M]

The across the line cap should ideally be an X or Y rated safety cap. You can get away with a quality 630VDC rated cap (I often do that on my sets), but I try to use X or Y for sets I plan to sell or repair for others.

[zeno]

The cap between the hoz out C & E needs to be the right type
otherwise it will short. Sorry I dont remember what its called
but someone will pipe in I am sure. We always used the OEM part.

When ever you see these white caps get rid of them. They are most
common in Zenith, GE & Maggy 1970's solid state sets. This includes
4 lead caps in the hoz out. They can cause total destruction under the
right conditions.

73 Zeno
LFOD !

[joe111671]

Originally Posted by Electronic M

The across the line cap should ideally be an X or Y rated safety cap. You can get away with a quality 630VDC rated cap (I often do that on my sets), but I try to use X or Y for sets I plan to sell or repair for others.

Thanks for pointing that out, I learned something. The only time I've heard of safety caps is regarding Zeniths and runaway HV. How critical is the value? I looked through my stash of used stuff and found a .1uF @275v with X2 on it. I'm replacing a .047.

Originally Posted by zeno

The cap between the hoz out C & E needs to be the right type
otherwise it will short. Sorry I dont remember what its called
but someone will pipe in I am sure. We always used the OEM part.

When ever you see these white caps get rid of them. They are most
common in Zenith, GE & Maggy 1970's solid state sets. This includes
4 lead caps in the hoz out. They can cause total destruction under the
right conditions.

73 Zeno
LFOD !

Glad you mentioned that, I would have just used the ones I ordered from justradios.com, which are described as "Metalized Polypropylene Orange Dips". I'll hold off then.

[CrtsRtubular]

I don't know if you still need it but heres the sams: https://drive.google.com/file/d/1fhv...ew?usp=sharing

[joe111671]

Originally Posted by CrtsRtubular

I don't know if you still need it but heres the sams: https://drive.google.com/file/d/1fhv...ew?usp=sharing

Thank you!!! All I had was the schematic pasted inside the cover. This is great to have. Much appreciated.

[Electronic M]

Originally Posted by joe111671

Thanks for pointing that out, I learned something. The only time I've heard of safety caps is regarding Zeniths and runaway HV. How critical is the value? I looked through my stash of used stuff and found a .1uF @275v with X2 on it. I'm replacing a .047.

Across the power cord safety caps aren't very critical. Going up in value is better than going down.

[joe111671]

I couldn't find anything to replace that safety cap other than NOS OEM replacements on ebay which I'm guessing are no better than what was in the set. So I used the ones I ordered. I put the set in series with a 100w bulb and this is what I got. It has sound and this horizontal bar toward the top that collapses to the center of the screen when I power it off. So it may or may not work, but I'm not sure whether I should just give it full power, or if this is a sign of something. Anyone have an opinion on what I should do from here? I'd hate to ruin it since it's got life now.

[JohnCT]

Originally Posted by joe111671

I put the set in series with a 100w bulb and this is what I got.

Hell man, do what Scotty would do! Full power captain!

Worse case is the cap will short and blow the fuse. It's when they open that you get collateral issues, and that shouldn't happen in any case.

John

[joe111671]

Originally Posted by JohnCT

Hell man, do what Scotty would do! Full power captain!

Worse case is the cap will short and blow the fuse. It's when they open that you get collateral issues, and that shouldn't happen in any case.

John

Ok John! Full power and I got a picture. Crude and no color, but a picture!

[joe111671]

A little fiddling and it seems like it's going to work. All the controls are touchy so they'll need to be cleaned. The brightness and contrast controls seem reversed, they have the opposite effect of what they should, but I can't complain about that.

If it holds up, I'll use it sparingly. I've only been able to find a couple pictures of these but never saw one with a picture.

[JohnCT]

Originally Posted by joe111671

Ok John! Full power and I got a picture. Crude and no color, but a picture!

Ordinarily, I would suggest checking the dilithium crystals for cracks... The good news is the tube looks strong.

John