I was given a P220f that had a blown LM2412 video driver (dead short from Vcc to Ground). One of the transistors just in front of it was also blown. Replacing those and cranking the screen control around produced a picture that was washed out and overloaded, but all three colors were there.
In the process of trying to find out what else was wrong with it, the replacement LM2412 failed in exactly the same way -- sudden dead short, letting the magic smoke out -- and I wasn't even poking around the video at the time, I was plugging the monitor cable into the computer. I guess it's possible that the "transient" from application of video is what did the deed.
I suspect that the LM2412 failures are somehow related to whatever the real problem is, but without a schematic, I'm reluctant to keep on feeding the thing 2412s in order to find out.
Any suggestions, or, can anyone provide a schematic of the video module?
thanks, Isaac