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  #16  
Old 08-07-2008, 09:43 PM
MRX37 MRX37 is offline
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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...
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  #17  
Old 08-07-2008, 10:15 PM
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radiotvnut radiotvnut is offline
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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.
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  #18  
Old 08-07-2008, 10:34 PM
MRX37 MRX37 is offline
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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.
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  #19  
Old 08-07-2008, 11:17 PM
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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.
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  #20  
Old 08-07-2008, 11:35 PM
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...

Last edited by andy; 12-06-2021 at 11:50 AM.
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  #21  
Old 08-07-2008, 11:46 PM
MRX37 MRX37 is offline
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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.
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  #22  
Old 08-10-2008, 10:30 PM
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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
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  #23  
Old 08-11-2008, 01:09 AM
MRX37 MRX37 is offline
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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.
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  #24  
Old 08-11-2008, 05:25 AM
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I'm not sure God has anything to do with some of these newer sets...
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  #25  
Old 08-11-2008, 08:14 AM
MRX37 MRX37 is offline
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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.
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  #26  
Old 08-11-2008, 12:49 PM
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Well, as they say, when life hands you lemons, make lemonade. My problem is that I try to keep making wine!
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