I have a system that ran great for a year but then for an unknown reason keeps shutting off without reason. It powers off completely. The only way I can get it restarted is to unplug the power supply and turn the power supply switch to off. Then replug the AC back into the power supply and turn the ps pwr switch back on ... then start the computer again. It is almost like the power supply is resetting for some reason. I have replaced the power supply (500 watt) with another brand new power supply 550w. The system runs fine and logs show nothing happening except just a hard power off. I do have it plugged into an APC UPS. Any suggestions of what to look for????
Tyan S2469 Motherboard - dual processor -