Power supply won't turn on after shutdown

[timbalaya]

I upgraded the RAM and a hard drive in a system I am using as a server. I also dropped in a new Antec NeoPower 500, since the old 450W PS didn't have enough SATA connectors. I also upgraded to Win7 Pro 64-bit from XP Pro. After I got everything set up, I shut the server down and moved it to its usual home. When I pressed the power button to turn it on, it would not start up; the CPU fan would spin for a second, but that's all. With the old PS put back in, it started up without a problem. Why would the ANTEC PS do this? From reading various forums, I gather I could have left it unplugged for 20-30 minutes, and it probably would have started up again, but what is the reason for this? Any help would be appreciated.

Thanks,
Tim

System specs:

Gigabyte GA-MA78LM S2H mobo
AMD Athlon64 X2 4800
4GB RAM (was 2GB)
WD Blue 160GB SATA HDD (was WD 40GB IDE)
2x WD Green 500GB SATA HDD
Samsung DVD burner (IDE) during OS install, no longer connected

 

[RetiredChief]

Total guess.
Is it possible that the atx 4/8 pin or the 20/24 pin connection was not so;lid and moving cause a lose of continuity, which would have been corrected when replacing the PSU. I would try the new PSU again, but also inspect the sockets (connectors from PSU) for a bad connector. Make sure it is seated firmly.

While there go ahead and make sure all other connections are solid, maybe even reseat memory and cards.

 

[timbalaya]

I did make sure that the RAM was seated properly (there are no cards)and all cables were firmly connected. The PS made it through numerous reboots during the OS install, but couldn't come back from a full shutdown. Other forums seem to hint that it is a fairly common occurrence, sometimes on new builds, sometimes on established systems, but I could not find a good explanation as to why. I suppose it's possible there just isn't one.

Either way, I picked up a SATA power adapter, and I am set up on the generic power supply which has been going strong for two years, 24/7, without a hitch. The Antec will stay in its box until my next build.

 

[RetiredChief]

Sounds like it is a PSU problem.
Not sure if it is a good idea to "Keep" it. Might be better to RMA it.

You could use a Digital volt meter to measure the output voltage to verify that they are in specs. The +5 and +12 V are very easy - Can measure at the molex connector. The 4/8 pin ATX and the 20/24 pin connections are a little more difficualt, but doable. This voltage would be close to idle condition and may not represent "under load" conditions. There is also a PSU tester (Approx $20), but I'm not a lover of these.