500W ATX PSU (check description) (SM2)

This PSU likely has a fault. Please read the description before asking for it.
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This 500W ATX PSU was removed from a PC I was using as a server, which therefore ran 24x7. I noticed that sometimes the PC had shut down by itself. If I turned off the mains and turned it back on, it started again and ran normally.

I had an old PC on hand and swapped its PSU in, and this seemed.to have cured the problem. The replacement has a higher power rating, so it could have been an issue of load.