I just got a Jetway Reman'd motherboard in the mail a week ago and I started having problems with it a few days in. One morning I started it up and it just froze hard while playing Bioshock. Restarted, tried to boot windows, froze. Restarted, no video. Restarted several times/power cycled. Got video, BIOS states memory did not pass testing and downclocked to DDR 667 automatically. Ran memtest86 and found a ton of errors. Replaced RAM with good set and ran fine until today. Tried running F.E.A.R. 3 and it blue screened and froze. Restarted, no video. Restarted, same stuff as before. Did this thing eat another set of RAM!!?? Even freezes sometimes in POST or BIOS menu. The other suspect is the 5-6 year old 500W Dynex power supply that's been running it for years (not without some issues). I'm thinking the mobo is toast or the increased load is pushing the PSU to fail. I'd appreciate any suggestions.
You say your PSU is "not without some issues." The PSU has to be perfect, just like everything else in the computer, but more so. Replace it if it has even a single "issue". This isn't like having a car you have to jump start from time to time, it's more like having a helicopter where the blades fall off every so often during flight.
I'm not overclocking. I replaced the motherboard because I got a Phenom X4 9500 out of another machine, that and the old motherboard had blown one of the capacitors on the CPU power side. I went from a Athlon 64 X2 4200+ Brisbane 65W to a Phenom X4 9500 95W. I also still have the ATI HD3850 graphics card installed in it. Do you think the extra 30W is causing all this? About the power supply, yeah it's had it's problems... Like the time it shorted out after one of the 12V lines fell out of the floppy connector and touched the computer case, or the time I tried to run a HD4890 on it.