My oldest PSR 3000 started acting weird infrequently. It would shut down and sometimes reboot..other times I had to reboot it manually. I thought, for sure, it was the power supply. But, after using another power supply it happened again and more frequently.

It went into the shop and $152 later it has been working fine. According to the tech the problem was some kind of chip...or pretzel...or something. (Can you tell I am not much of a techie?)
Eddie