I have a Dell PowerEdge 860. Got an 2008 R2 running on it. Here is the scenario I'm currently in:

I can boot it up and work as usuall. But when I restart it, it just shuts down, doesn't reboot, and it won't boot up again. Then it stays in this "mode", On/off button blinking green(standby mode?) and System Indicator LED blinking amber. If I try to press the On/Off button on the frontpanel it won't boot. It's like you can hear the fan from the PSU running but nothing else is trying to boot. If I unplug the powercable and then put it back in again it's the same, the extremley noisy fans won't start and it's just sitting there.

If I let it "rest" for like 1 to 24 hours while the powercable is unplugged and I plug it in again, it boots directly, without me having to push the On/Off button.

What I have tried:

• Run diagnostics(not the one in POST phase) and everything is fine
• Booting without any cables except the powercable
• Boot without memory installed
• Boot without the raidcable plugged in
• Cleared NVRAM
• Reseated all the components and cables
• Googling like a freak for any possible solution
• Tried Dell Support but I don't have any warranty left so they can't help me unless i pay some ridiculous amount of money I suppos

Do anyone have some experience with the same issue? Do I need to replace something or is there any other way to determine the problem?

Any help will be greatly appreciated.