Well, you either got a DOA motherboard or you damaged it or the processors while installing the processors.  I would test with the old board before telling the seller they sold/sent you a DOA board.  That's my two cents.
We have a Poweredge 1850 that had a 0RC130 motherboard with two SL7ZF CPUs installed. It ran fine, but one of the memory slots was shorted so we ordered a replacement motherboard. We received a 0D8266, installed it, and now we get nothing when powering up. I've tried reseating the CPUs and booting from one CPU at a time without the memory installed and it continues to simply sit there with the fans running after I power it on until I shut it down. Is it possible that something is incompatible with the board, being that it isn't the exact same make? Or is it a greater liklihood that we received a bad motherboard? Thanks.
Issue upon motherboard replacement