I have a Sony KV-35S26 that I acquired with a bad power supply and shorted HOT. It was deader than a doornail.
Using information acquired from these posts, I replaced two switching transistors in the power supply (2SC4834), the HOT, and the blown fusible resistor (0.1 ohm R607) on the power supply.
Voila! The television works great--except . . .
After the set is on for a while, all of sudden the right side of the picture starts to contract and cave in. Then the horizontal deflection gives way to a picture that contracts into the middle and goes black. At this point I've always quickly turned off the set, assuming that if something's not oscillating I'm probably on the verge of shorting out the parts that I just replaced.
I let the set sit--sometimes for 30 seconds, sometimes for a couple of minutes--and when I turn it on again I once more have a very nice picture. Then after another few minutes of running, the same thing happens again. It starts to get fuzzy and contract along the right side, and then it collapses.
I should also mention that when I replaced the HOT, I also went through the HOT circuit and meticulously resoldered every connection (there were a few that looked like they might have had ring cracks at the solder joint). I also resoldered the flyback transformer.
The intermittent nature of the problem after the set's been on a while makes me wonder if it's heat related. In addition to the components mentioned above, are there other common failure points in the horizontal output circuitry?
I sincerely appreciate any help you might be able to offer.
Best wishes, Juan