Having issues with a Poweredge R300 server, it came from a working environment but has suddenly stopped working with a E1410 CPU 1 IERR, I have so far tried the following:

RAM re-seat

Different CPU (X3363 originally and also tried X5355)

Tried without PCI-E cards

Tried without the Riser Cards.

Tried another Motherboard pulled from a working R300.

The only other thing I can think it a faulty PSU, does anyone have anymore ideas before I go down that route?