Sony KV-24FS100 television Chassis BA-6
I agreed to look at this set for a friend at work and I am sort of stuck. She said she was watching it just fine, glanced away, and when she looked back, the top half of the picture was gone - just black. I fired it up and find that the top half has collapsed. The bottom half is just fine - full color, no foldover into that area, etc. I do, however, find that if I hit the tv/video button on the remote, then in what I presume are the video modes, the whole screen collapses into a horizontal line at the middle. Keep pushing the button and when it gets back to the tv mode, the bottom half returns.
I searched for this issue online (here and otherwise) and not found it mentioned anywhere, so I started in. I found and downloaded the service manual, so I have the schematics. The first thing I checked was the electrolytic caps around the vertical output chip (TDA8172). ESR was way high on 2, and marginal on 3 more so I replaced all 5. I also checked all the resistors that attach to that chp and all appeared to pretty well match the schematic. No change in action.
So, that's where I am now. My next thought is to replace the TDA8172 chip, but I would appreciate the opinion of the more experienced people here. Any thoughts? Thanks.
WT