GE Portacolor II needs help
 

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.

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

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

73 Zeno:smoke:
LFOD !

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.

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.

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:smoke:
LFOD !

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.

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.

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.

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

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.

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!

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.

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

John

The dilithium crystals are always the first thing I check. Haven't had a bad one yet! ;-) The tube is definitely strong, despite it having instant on. It's the first solid state set I've had that has it. I'd disable it if I planned on leaving it plugged in, but I have to say that it's really cool to have a set just pop on immediately. No other TV to this day can do that.

What am I missing here! What is a dilithium crystal?
I guess I'm still stuck in the past!

As best I remember, they were a rare material that featured in various Star Trek series.

Yes, two hundred years in the past! LOL, the dilithium crystals were an exotic mineral that more or less powered starships in the Star Trek universe, or at least the energy from the matter/anti-matter engines was funneled through. A continual plot device where they were always in danger of cracking, burning, etc. I guess they never thought of carrying any extras...

John

My brother was in the Nuke business. Worked for Maine Yankee,
Westinghouse, Combustion Engineering. He knows about dilithium.
As soon as the pols figure out how to tax it & create a massive
bureaucracy we will have it. The military already does.

73 Zeno:smoke:

Behold the dilithium. :D

I never was much of a "Trekkie". I worked nights and never saw much Prime Time TV, at the time. :scratch2:

OT, but that may be the best color I've seen on one of those!!

John

Agree with that. All these early GE SS sets were plagued with HOT, FBT
yoke & vert problems. Other than that they ran fine & were a BIG
improvement over the trashy tube chassi. It would be fun to work on
one again.
Oddest thing was the shorted yokes. These sets had the least amount of wire & were wound wide open. I looked at a few shorted ones & couldnt find where.

I was about to post the same.

Off topic related note: I bought a 1996 Nissan Sentra from Honda of Cleveland (Tennessee) some years ago. The financing was through Combustion Federal Credit Union from Chattanooga, Tennessee (Combustion Engineering had a plant in Chattanooga, Tennessee). So I was a member of Combustion Engineering's Credit Union. The car was excellent, lasted 140,000 miles until hit from the side, and was reliable. $5000 well spent (and the trade in of one near death Chevy Astro Van, a 1993)

The General spec'd some of the worst pots on the Portacolors & similar sets. Every one I've had, including the later AA/AB and the larger C2/CE had very flaky controls.

I'm very impressed by that picture; I didn't know that CRT was capable of it!

The original portacolors have a tendency to grow tin whiskers and short out their own pots... after a heap of troubleshooting on one that had a dead IF I finally figured out it was the AGC pot and adjusting it with some contact cleaner brought it back.

Zeno, any theories on why they had those issues? It makes me wonder if was bad design, or inferior parts. I also wonder why they scrapped it and kept making the tube chassis after this, when they performed better than the tube ones.

I found an ad that featured both versions, the SS model was $20 higher. Was 20 bucks enough to keep them from selling well?

I'm not sure there's a tube portacolor in that ad... The set says "68% solid state" the tube portacolors only had one transistor in the UHF tuner... unless they are doing some decietfull advertising BS and counting SS diodes against the compactions, and even that doesn't seem mathematically possible, I don't know how they could come up with %68 solid state.

I had a boss that just made numbers up. I'd listen to him tell people a certain TV had 799 lines of resolution...I could hear him saying a TV was 68% solid state!

The 19" looks like an C-1 IIRC. Its 99% tubes. The SS porta color
was JA or QA chassis. One was also used in a 19". Both were short lived.
They also had a 16" that used its own chassis. It was a real dog. Tubes.
Never saw one that ran right.
Next steps were modular chassi for 13" & up. Latter a one board chassis
AA, AB, & AC. Used in 10, 13, & 17" sets.

GE was improving slowly. One more total POS 19" chassis the EC. Then
the rest were good as any. And just like Admiral when they got it down right
they soon stopped production.

73 Zeno:smoke:
LFOD !

I bet that's exactly what they did!

Mine is a JA. I've put a good 40 hours on it and it's still going so I'm calling this one good. I think it's a keeper.

I have a Zenith from the same estate sale that I haven't done anything with yet. It looks like it needs power supply caps, so I ordered those when I ordered the ones for the GE. I'm going to start on it next and make a new thread. Thanks to Tom C. for the schematic.

Wow that Zenith has a real strong jug. It will come out real nice.
On that set look at the main choke in the power supply. See if it has a
non polarized electrolytic in series with a resistor. This is in parallel
with the choke. Per Zenith factory its not needed & you can just
snip the cap out.
2nd thing especially on tin can Zenith sets. The ends of the terminal strips go to ground. Sometimes ones in the middle do also. They can break loose &
causes intermintants especially toward the front under the CRT. Even a
hand wired set can get a cold joint !
Let us know how she comes out.

73 Zeno:smoke:
LFOD !

Good to see that Zenith working.

I posted the Zenith set in a new thread: http://videokarma.org/showthread.php?t=273762