Zenith Chromacolor II 19JC60Z - Videokarma.org TV - Video

maxm · #1 01-23-2022, 08:05 AM

I have a 1977 Zenith Chromacolor II Space Command 19" set, model SJ1939W, chassis 19JC60Z. Sams 1740.

It was working pretty well, but the picture would sometimes shake / flicker vertically, like the linearity was changing. I checked some of the electrolytic caps and solder joints on the modules (all were good) and also reseated all the modules. Now when powered on only the degauss, CRT filament, and channel number light come on. It appears these are the functions that don't require the power supply module. I reseated the module, but no change. Should I suspect something with that module?

zeno · #2 01-23-2022, 08:58 AM

You still get sound if the 130 V dies.
So check the 24V at the regulator transistor. Should be apx 24 V on all 3 pins.
The 2.2 ohm & Zener ( 103-105 iirc ) were also known to go.
Also 8the 9-86 color module can go in upside down & blow the
regulator. OOPS

73 Zeno

LFOD !

maxm · #3 01-23-2022, 11:49 AM

Oops! The 9-86 was in upside down. I should have paid more attention and looked at the diagram instead of assuming the text went in right side up. I put it back correctly and the set works again, I guess no damage done. The vertical problem has also gone away for now.

Jeffhs · #4 01-23-2022, 10:04 PM

Quote:

Originally Posted by maxm

Oops! The 9-86 was in upside down. I should have paid more attention and looked at the diagram instead of assuming the text went in right side up. I put it back correctly and the set works again, I guess no damage done. The vertical problem has also gone away for now.

I am amazed the module wasn't severely damaged or destroyed if it was plugged into the socket incorrectly. I'm sure if there were any kind of high voltage in/on that module socket, the set's line fuse (if it has one) would have blown instantly, or else the module itself would have been permanently damaged. Solid state circuit modules, as I'm sure you are aware, are nowhere near as forgiving of mistakes as were components in older, tube-type TVs. I don't know how long that 9-86 module was plugged into its socket incorrectly but in any case, you were very fortunate there was no damage, and the TV now works as it should. That the module was plugged in upside down could explain why there was a vertical problem, as well; however, I will say again you were extremely fortunate this mistake didn't damage or destroy other parts of the TV.

Electronic M · #5 01-24-2022, 12:25 AM

Back when I was a teenager and didn't know much about solid state I plugged one of the ICs in my vintage Atari 2600 in backwards...And for a few years thought it was broken...A friend found my mistake and amazingly after plugging the chip in correctly it worked fine... Sometimes SS parts will survive abuse you wouldn't expect them to.

dishdude · #6 01-24-2022, 12:30 AM

Some of those circuits run at such low voltage it doesn't have enough juice to fry anything.

ARC Tech-109 · #7 01-24-2022, 08:13 AM

I'm still trying to wrap my head around the vintage part of ATARI 2600 Electronic M

Electronic M · #8 01-24-2022, 01:32 PM

Quote:

Originally Posted by ARC Tech-109

I'm still trying to wrap my head around the vintage part of ATARI 2600 Electronic M

I was born the last year that you could buy a 2600 new...and my dad grew up playing one as a kid. As a teenager playing a 6 switch model that was new when my dad was that age... Vintage was a kind description and Antique would have been slightly brutal (though I was starting to see 70s stuff in antique shops back then, and given some Ataris are 50 now it's certainly appropriate now).