jaquith :
Yes, PSU = Power Supply Unit.
I replace Power Supply same thing Black screen No Post No BIOS no beeps just flashing light on from for a second then all stop then trys to restart again.
Sun Ultra 24 Workstation.
Next Step? Take out all video cards see if boots,
take out ram chips see if boots,
Thing has a battery in it someplace see if it is dead I guess?