Sony has a white vertical line running down screen on video channels (ports) 1-4. Video port 5-7 shows no line. Cable television is viewed on 5 with no problem.
Interchange the video channels 1-4 and 5-7. Now check white vertical line in video port 5-7. Suppose you get problem remove cable television cable from tv during another two port running. These type problem occurs only when RF disturbance from cable television or video ochannel ports cable wire ground problem. I found there is no problem in tv. External source only the problem. I hope above details give you the better solution.
Basic LCD monitor and TV troubleshooting guide:
Failed TV and Monitors pictures: http://s807.photobucket.com/albums/yy352/budm/
Learn about bad caps: http://en.wikipedia.org/wiki/Capacitor_plague
Capacitors kit: http://lcdalternatives.auctivacommerce.com/ he can make you a set of caps for you.
Or www.digikey.com just make sure to use caps with low ESR, 105c, high ripple current, long life rating such as PANASONIC FM or FC series.
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