Hi, This set suffered a high voltage damage when the local power company sent the line voltage up to 150 volts. I got them to admit that they screwed-up and they bought me a new set. However, before all this fiasco it was a good set so I got the service manual and looked up the problem. The standby LED flashes four times, pauses then flashes four times and repeats this cycle.

SM said no 13V supply IC502 faulty on the A board. Changed IC502 - no change. Replaced the A board - no change. Has anyone ever worked on one of these sets? Should I just trash it?

It looks like you tried everthing I would have. I picked up a Sony simular to yours three years ago. I don't have experiece working on them, as the set worked perfectly when I got it. The ironic part the set was exactly five years old to the day I bought it. The former owner bought it in 2003. They had the date written on the owners manual.