On a recent walk I spotted this out by the curb. It has a 760GM-P34 motherboard, 8 gigs of DDR3 and an FX4130 CPU. The hard drive, optical drive, and PSU had been removed. I put my cheapo spare PSU in it, and it powered up without any issue.
Edit: Loading Windows 10, I discovered the problem - on rebooting after an update, it would lock up, and when you hit reset it would reboot, but not be able to detect the hard drive. I thought maybe there was a problem with the drive I used, so I tried another, but the issue persisted. It seemed like a heat issue, so I used a stock copper/heatpipe AMD cooler I have with fresh Arctic Silver, but it still did it. I swapped in an FX 4300 I have, and removed and reseated the RAM, it still did it. I noticed that the northbridge heatsink, which is large and fanless, was pretty hot. I removed the motherboard, popped that heatsink off and cleaned it and reapplied thermal paste, and that finally resolved the issue! Now running Win10 with no issue.
"Everyone is ignorant, only on different subjects." - Will Rogers