If it has been off for a long time, it will boot.
Reboots work fine. Sleep and coming back from sleep work fine.
But if I shut it down and then try to turn it back on, it does nothing. For a number of seconds, I can hear a very very faint high pitched noise--like power/capacitor/something or other so it registered the button push.
Suggestions on troubleshooting?
It's an old dual proc dual core opteron 885, K8WE motherboard with 7 GB RAM.