Mitsubishi model: VS 50607 projection TV had a great picture. When I turned it on the other day, a white smiley face came across screen on the upper 3/4 part of a screen. seemed like created by RGB lines. Rest of screen is black. No sound or picture in background. Power stays on for about 15 seconds then powers itself off.

Any suggestions or known problems for this box like projection TV?

Rick,

As was previously suggested, take a look at the Convergence IC. It might be an STK393-110 (or something close STK393-xxx). It will be mounted on a very large heatsink as these things get really hot.

Check for bad solder connections on the bottom of the printed circuit board.