Hi guys. My Mac Pro early 2009 (8 core) had upgrade firmware from 4,1 to 5,1. (but the CPU is still E5520.) 2 month ago, the backplane board is not work (the backplane board shows "631-1009"). I would like to buy a new one from eBay. so, I have to buy a "631-1009" backplane board to replace the old one, right? if I buy "631-1427", can it work? Thank you.