picture light to dark and back

[Rocguy]

Hello there. Toshiba Cinema series Model CN27C90. Occasionally when I first turn it on the picture looks like it's in letterbox (black at the top and bottom) however after a few seconds the picture snaps in ok.
The main problem is that now it's started to just fade from light to dark. It's like when you used to try to record a VHS tape that was protected with macrovision. It started sometime yesterday but only did it a couple of times. This morning when I turned it on it started shortly after turning it on. It stayed dark longer than it did yesterday as well. This went on often for about 40 min. After that it hasn't done it since. It did it with different inputs even. Input 1 and 2 DVD, cable, etc. It's definitely the set. Now last night it went dark after being on for hours. Any ideas?

[Guest]

This has become worse. It now only displays for a little while then the picture goes out. Sound keeps going. Any ideas?

[cory]

not sure abot light to dark,but sounds like poor solder connections on main pcb.letterbox problem,resolder vertical ic and check for other poor connections.