How long have you had the set for, and when did the problem occur?
Was it after a storm or power outage?
Does the standby/timer light blink continuously, or in a pattern (such as 5 blinks, pause, 5 blinks, pause, etc.)?
I worked on it last night but cannot get any DC voltage out of the connectors off the power board. I checked the AC voltage IN to be sure there was power into the tv and that my tester was working correctly. That did show voltage in the 90v range but not the 125v that I was getting from the outlet. Why the drop with a standard 6' cord?
I checked all of the capacitors before I even contacted you since I have been able to replace blown ones and repair tv's for friends in the past but maybe I'm in over my head now. I wanted to at least let you know I'm still in but I need to try the tests again from the start tonight and see if I can get some readings out of those connectors.
There shouldn't be any AC drop from the wall to the power supply. Disconnect the cord from the TV and test at the end of the cord. Also double check your DC voltages coming off the other side of the power supply board, and let me know if you're getting anything. You should have 5V, for sure.