What can be wrong on a 4.1 tray? It's only on the CPU B side. It's not the CPU, swapped several times. It's not the memory, swapped as well. With another tray everything is fine. I know this tray has been sitting in a computer who ran hot, it killed the CPU B, replaced it, but something else is damaged as well! What can it be? (it runs fine with only CPU A in it) I have several trays, they all run fine, except this one! No red diagnostic lights btw!