TV turns off and standby light blinks. Blinks 3 times, pauses, blinks again 3 times.
Three blinks means technically 'B+ over voltage protection (OVP), unit goes to the standby mode then displays the 3 blink fault. This is also a problem in the power supply circuit, check T603 and R672.'
After a little more research i found this comment:
"Guys I have found the problem. (referring to T603 and R672) I have found mine anyway. When I replaced my projection lamp, I failed to push the lever all the way down, but this was not the problem, just something you need to be sure to check. The problem was the lamp door. This needs to be shut properly. I found another thread where a guy had tried the same thing. It worked. The door clicks hard at the end to set itself. This worked for me. Hope it helps you."
IMPORTANT: After you repair the unit, you MUST clear the values on this diagnostic screen. These codes do not reset themselves after the fault is corrected, so if you don't clear them, you'll be seeing "old" fault codes the next time you enter this screen. Clearing is done by going into the service mode (display, channel, 5, volume plus, then power ). Press 8 and Enter, which returns everything to the factory preset condition.
So my question is have you replaced the lamp?
Hope this helps