Power off, remove AC for 10 or so minutes and try again.
TEST #2. Does the OSD work? (as you are now a TV technician I'll use abbreviations techs use daily.)
If the above fails my guess is a mainboard failure. Not user serviceable, get estimates.
Hi guys,
while watching tv yesterday, the screen abruptly turned green and grey and gradually changed to complete pixelated grey scale.
I tried powering down for the whole night and reconnecting everything, but did not help.
http://i66.tinypic.com/2u8f1mt.jpg
Greatly appreciably any help to debug this issue
thanks
Rahul

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