I've moved a Dell PowerEdge 2800 to a new server room, now it hangs during Power On Self Test, failing to move the progress bar further than the "O" of "BIOS". No useful error messages, neither on the screen nor on the tiny LCD at the front.
I've swapped RAM modules, tried to clear the NVRAM, tried to boot with only one pair of RAM modules, swapped PSUs, tried to boot with only one PSU, tried to boot with and without harddisks, I even tried removing the DVD drive. Nothing helps.
I can't find useful information on the Dell website. Dell Trouble shooting information rely on beep codes or information on the tiny LCD, but the server does not beep (except when I remove all RAM) and it does not show anything on the tiny LCD.