I think you might have dry solder joints on the line output stage but if this does not solve the problem then it is a faulty component on the line output stage. If you can do it check for yourself otherwise find a competant technician. Hope this helps.

Hello, i am no pro but i have a 30 proview that did the same thing and i went through changing perfectly look capacitors and didnt not sovle the issue. i slowly kept trying to figure it out and ended up looking into the transformers(rectangle black things) on the inverter board after changing all the capacitors on the inverter board that did nothing. the transformers checked out fine but would jump around -so i read online that sometimes the solder joints dont do so well from the factory.so i did my best to clean all eight legs on each transformer and resolder. THe tv works fine after that-lucky?maybe but you never know-by the way my tv would go on perfect for anywhere from 5 sec to 2 ;min before shutting off video-