My 3 year old KDS-R60XBR1 had worked flawlessly ... until August.

Then, it started acting up. It would start up, run with a normal picture for 1-2 minutes, then go into standby. I assume it is in standby, because the power/standby LED starts blinking green continuously for 1-2 minutes (just like when you first turn on the power) then the picture reappears.

This would continually repeat: 1-2 minutes of picture, then 1-2 minutes of standby.

So back in August, I vacuumed the vents I could see, and blasted compressed air from a can into the fans. I removed the bulb, it had a VERY thin coating of dust, blasted it off, reseated the bulb. This fixed it for a month of so.

Now is is doing the 1-2 minutes on / 1-2 minutes standby thing, and I can't cure it with a vacuum cleaner and compressed air. I even piggybacked 5" 12V computer fan onto the big fan on the back, for extra exhaust suction. Still no luck.

Any ideas on what to do?

Thanks in advance.