also, look at the capacitors on the mainboard for any signs of failure.
Well i did do that a couple weeks ago when the issue first started and all the caps look good. The motherboard is refurbished and i already started the return process because it's only been a couple weeks. But I think it may be an electrical problem in my house as it is an old house. I wish I knew more about electricity. From what I've read it could be noise in the lines causing unstable voltages. But again, why is it just the one system that is affected?
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the surge protector may have been to close to its limits.
the 850 watt system was always pulling close to 700 watts...
so you were close to the surge protectors limits using 2 pc's
Actually, I switched the 500W system to the wall (same receptacle) to test that theory and it is still happening when I switch the box fan speed (plugged in to the adjacent wall receptacle) the system hangs and the display goes out.