Our Mitsubishi 65" DLP model WD-76534 tries to turn on, but the screen will not light up. I did the self diagnostic error test from the service manual and got a '66' error code. I also read some more & watched videos online about these TVs. After reading a few suggestions people gave on Youtube videos of the same problem I'm having, I decided to try replacing the lamp ballast. I ordered it, and replaced it the other night, but it still does the same thing. I hear a rapid clicking (possibly the "arc" trying to start the bulb), but no picture. There is also a faint sound like a whistle sound effect for a bomb dropping. I tried the factory reset and to put one of my new spare replacement OEM DLP bulbs in & same thing; no picture.
I was just wondering what else might be the problem, or what to try next. By the way, error code 66 says most likely causes are 1. Loose J4 connector, or 2. Lamp cartridge or connection to lamp.