Computer was working fine as of about 9PM. Left it running and went to put the kids to bed and watch CSI. Came back around 10:30 and its off. Try turning it back on - nothing. No lights, no beeps. Not even the LED on the network interface. Nothing appears burnt. No bulging caps. I'm thinking power supply, but it seems odd that it would just die like that. Thoughts? I will try disconnecting everything but the CPU and one stick of RAM, but I'm not optomistic.

For what its worth, its an IBM Intellistation M (6230-20U). Has an MS-9128 motherboard (OEM). Power supply is AcBel 340W.