Sony KP-43HT20 - I do not believe my convergence ICs are at fault.

Addendum:

Only the RED "flakes out" - it works fine for a while, then jitters a lot and goes WAY OFF. I just pulled the board and resoldered EVERYTHING near the leftmost convergence IC, after cleaning that area with rubbing alcohol. The problem remains.

I'm leaning toward a capacitor but haven't decided which one.

Cycling the power brings it back for a while...

The ICs could be bad, drifting as they heat up. But I don't blame you for not wanting to perform what appears to be a shotgun repair.

You are either looking for a bad connection or you have a bad IC. Very rarely you could have a problem in the convergence generator.

There is much information about these problems and repairing them in the first ten posts here:

Leonard

Well, they often do get bad solder connections at the IC's themselves, caused by heating / cooling over the course of time, or one IC could be opening up internally as it warms up.

We have done lots of these, and some were intermittent. If you get the replacement IC's from a reliable supplier, you should be fine.

Mark Z.

The convergence ICs are the hardest working parts in the set. It's been my experience that when they go that's it. And depending on the design they blow fuses and/or smoke resistors.

I would rule out other problems before replacing these chips.

Based on what I've read so far, this set is of such a design that it blows a set of 3.15A fuses that look like yellow resistors.

All such fuses are good.

After re-soldering the IC, it ran for about 5 minutes before it flaked out again. I turned it off and back on, and it ran for another hour without the major problems, until I got tired of watching it and put it away for the night. I haven't tried it again today yet.

During that hour, it appeared that the red image was slightly larger than the blue and green images - ie, it was converged at some point nearish the middle of the screen (although, interestingly enough, not the exact center), and there was red to the "outside" of everything. I can't explain this too well, I guess, but "it looked like the red image was bigger than the rest" should give a good idea.

I know nothing about the history of this TV, so multiple problems are a possibility. After power-cycling, it ran fine for long enough that I actually got tired of watching TV. My next guess, on the "total loss of convergence" problem, is one of the four electrolytic capacitors in front of the IC. They're cheap enough that I'm just going to replace all four. I believe, however, that the "red image is bigger" issue is a second, unrelated problem? Possibly even more mechanical than electrical? I definitely need some guidance on this one.

I know nothing about the history of this TV, so multiple problems are a possibility. After power-cycling, it ran fine for long enough that I actually got tired of watching TV. My next guess, on the "total loss of convergence" problem, is one of the four electrolytic capacitors in front of the IC. They're cheap enough that I'm just going to replace all four. I believe, however, that the "red image is bigger" issue is a second, unrelated problem? Possibly even more mechanical than electrical? I definitely need some guidance on this one.

Is the red image "smeared"? If so, check the electrolytic caps on video drivers.