I've been having a problem with my 14y/o Mitsubishi VS-585R 50" rear projector TV - It's performed pretty flawlessly through the years; so far all I've had to replace on it was the sweep board. Lately,though, and with increasing frequency, it spontaneously turns itself off, sometimes after having been on for quite a few hours, sometimes several times right after I turn it on in the a.m. There is usually a brief, sharp spike in the sound VOLUME just as it shuts off. I had the local Mitsubishi authorized repair people come and look at it but they said they had no idea what the problem was, which was not very encouraging. Basically told me I should buy a new TV, which is not an option for me at this point. That seemed like kind of a cop-out, and I just can't believe nobody's ever encountered this problem before. Any ideas on pinpointing the problem?!! Any help would be greatly appreciated!