Doa Psu?

I have an ATX form factor PSU - 300W - that I just got from some dude on eBay (cheap-o no-name for a relatively light-use PC).

I hooked it up last night and switched it on, and it starts to power up for about a second - fans spin, lights flicker, then it shuts right off. Voltage is correct, and I know it's not under-powering the system because it's replacing a 250W PSU that I gave to someone else. The only hardware diff from then is an 8MB Savage vid card replacing a 32MB TNT2 that I also gave to the same person - son in theory it should probably need LESS power than before.

Did I just get a bum unit?

Sounds like it.

Check the fuse in the plug, if its not that then email the guy straight away. Perhaps it got damaged in the post?

Bummer, man.

Thanks Rendy, I'll see about getting it replaced then.

One way you can easily test a ATX PSU is to use a paper clip to jumper/short out pins 14 and 15 on the connector. Should be a green wire that you are looking at and that needs to be shorted to one of the black ones. That green wire is the switch for the PSU.

*sighs* I miss jumpers...only way to know that card is set to the proper address...

There is another posibility, if you have not already scraped the unit.

I've had this exact same problem when I upgraded my mobo but kept the cpu, the problem was that the cpu was overheating because I had flaked off the dried out heatsink compound.

one burnt finger and some of that silver compound in the syringe later My cpu is running cooler than ever...

Just a thought..