ProLiant ML350 G3 powers off for no reason

[Sebastian Steiner]

Hello,

currently I'm experiencing problems with a ProLiant ML350 G3 server:
At first I can switch on the server without any problems. It boots the operating system (Windows 2000 Server) and I can work with it. But after a few minutes uptime the server shuts down: Windows 2000 performs a very quick shutdown - without saving configuration data etc. - which only takes 3-4 seconds. Then the server stays switched off for about 60 seconds. Suddenly it powers on again without any user action. After that it takes only 20-30 seconds and the server powers off again. In these cases the server doesn't even succeed in booting the OS. It already powers off when extension cards initialize.

I already replaced the 2 redundant power supplies but it didn't help.
Using the ROM-based setup utility, I disabled "Thermal Shutdown" and "ASR" but that didn't help also.

I think that there might be a temperature problem which makes the server power off after a short uptime but no component is getting hot notably as far as I can feel.
But another point that seems to support this theory is that the server stays powered on for a longer time if I keep it powered off before for a few hours.

The Remote Insight Log reports (my comments in brackets):
--
07/06/2009 15:25:51 Server power failed.
07/06/2009 15:23:54 Server power restored.
07/06/2009 15:22:35 Server power failed.
--

The event log of Windows doesn't show any hints concerning this issue.

The mains supply can't be the reason for this power problem because other computers in the same room have no outages.

Does anybody have an idea what I could try to get the server running again or does anybody know this problem?

Thanks a lot in advance!
Sebastian