My latest find is a 1992 Zenith Sentry 2 19" TV. When I first found it I thought "uh oh, 90's Zenith... CRT's probably shot.

Nope, the CRT seems to be fine. The horizontal isn't right though. The picture looks scrambled.

I want to fix this TV, cos I have a feeling it was probably one of the last Zenith's made with a decent CRT...

I'll provide a model # and images later.

Some of those Zenith's had a 2.2 (IIRC) uf cap going from pin 2 of the jungle IC to ground that would cause horizontal scrambling, tearing, lines, etc.

...

As promised:

The model# is SS5045Y

And here's a pic of what it's doing:

http://i119.photobucket.com/albums/o121/mrx3750/Zenith.jpg

On strong channels, it seems to only do it intermittantly.

That looks like the symptoms of that 2.2 uf cap.

Okay. I'll start testing caps soon. This TV's actually gone to the back burner, as i found another one that's actually worth something if i can fix it.

Changed my mind and started testing caps. Found one bad 100uf cap and replaced it... and the problem worsened! The bad cap measured at only 35uf while the replacement was a good cap.

In any case, is the Jungle IC a huge IC, or is it smaller? A pic of what it looks like would help.

EDIT: This TV has mostly black caps. there are a few light blue, which I have repl;aced. No burgendy caps though.

The jungle IC is the rectangular black chip with anywhere between 52 and 64 pins on it. It will probably be located somewhere close to the tuner.

The other big chip is the microprocessor and should be located close to where the front panel keypad plugs in.

What module number is in this set? It should be a 9-xxxx and will probably be printed on a label in the back of the set?

The module number is 9-1118

So the Jungle IC is a big IC, that narrows it down. That 100uf cap I replaced was near a small IC.

That jungle IC will likely have an LAxxxx part number on it. The microprocessor will probably have some strange combination of letters and numbers on it.

That jungle IC will likely have an LAxxxx part number on it.

Nope. Only two IC's that fit the description of the jungle IC, and neither has a LAxxxx part number.

...

If it'll help, here's what's written on both of the large IC's:

First IC:

221-679
Sanyo J9139 1JE0

Second IC:

221-685-02
130 J9148 (c) ZENITH 91

It's the first IC (221-679). It's the same as an NTE7054. Pin 30 is where the B+ enters the IC for the horizontal oscillator / drive circuit. Check any caps that connect to pin 30.

O...k... How do I know what pin is Pin 30? I don't remember how they're numbered.

Well, I fixed the horizontal issue...and it wasn't worth it.

The CRT is indeed still pretty bright... only because the brightness and contrast are at maximum. Worse yet, there's really bad color bleeding in the red areas of the picture, which I didn't notice at first because the horizontal was messed up.

So... yep, another bad 90's Zenith. Zenith may have been still making great CRT's in 1992... but this TV didn't get one of them.

I am quite pissed now. I spent hours changing out caps...

I know how you feel. I was once given a 27" Magnavox TV (back when a 27" set was still worth trying to sell) that had a broken PC board. I spent hours running jumpers across all the breaks. I turned the set on just to discover that the shadow mask inside the CRT was damaged. All I got was rainbows all over the screen. I'll never go to that much trouble fixing a broken chassis unless I have another chassis that I can use to test the CRT.

I wouldn't toss that Zenith just yet. If the tube number starts with A48, it's a 19". If it's an A51, it's a 20". Many of those 19" and 20" tubes from other brands of TV's will interchange. You'll be OK if the mounts are the same, the socket is the same, and the yoke will fit the neck properly. Many times, I've used CRT's out of other brand sets in a Zenith. By doing this, I actually made the set better than it was when it was new.

The CRT is an A51ACB02X.

I have neither the tools, nor the courage to attempt to swap the CRT.
The yoke is questionable too, as a quick convergence test showed bad corner convergence. (WHY AM I NOT SURPRISED?!)... just recently finished dealing with that on, yep, another 90's Zenith.

I'm shit canning this TV. Right now I don't want to even look at it. Tomorrow I'll salvage the board. maybe it has a HOT I can use in that Sanyo... doubtful but who knows.

Some of those Zenith yokes from the '90's had the convergence magnets made on to the yoke and the plastic would become very brittle and fall apart. Sort of reminds me of those old yokes that would fall apart on B&W sets from the '50's.

...

Oh, for future reference, the cap that ended up being bad was a 22uf cap rated at 16 volts, light blue in color.

It measured at around 19uf. Not very low, but I decided to change it anyway.

Ahh yes, the bonded yoke. That's one reason I sold my RCA colortrak. The picture was tilted slightly. A slight rotation of the yoke would have solved that, but noooo... And I wasn't about to risk imploding the CRT by trying to remove the glue.

Your multiple problems remind me of some 20" Panasonic TV/VCR combos model numbers PV-M2xxx something-or-another. I had several come into the shop at different times after lighting strikes during the mid-late 90's. After the fuse was replaced and the transistors that control the on/off relay replaced the set would power on...

... only to find there was no audio... or tuner... or vertical deflection... or something else... or all of the above...

I've never seen a model QUITE like that one after a strike. Very damage prone. I always had to shoot a little high on initial estimates because of that. I feel for you.
Brian

Well, its not all bad news. The Horizontal Output Transistor from the chassis is currently in a 36" TV I found. It's a (very) temporary replacement, but it lets me know that the TV has hope.

So, the Zenith died, but, god willing, the Sanyo will live.

I'm not sure God has anything to do with some of these newer sets...

Maybe not, but I did find both TV's on the same day, and by coincidence... or divine intervention, take your pick, the one that I couldn't save had a HOT with a damper diode in it, allowing me to run the 36" TV long enough to show that the CRT in it is still fine.

And if it turns out that another failed component is what's causing it to blow HOT's, I'll then have a spare just in case.

Well, as they say, when life hands you lemons, make lemonade. My problem is that I try to keep making wine!