Something to consider. A defective slot, DIMM, bent pins in CPU socket or defective CPU would probably result in code 55, CPU initialization failure or other error code.
A reboot loop without error can have more than one cause... hardware incompatibility, incorrect BIOS settings, memory issue, power problem, ground, or BIOS failure. While a defect is possible, I'd test with different RAM before concluding the board is defective.