Blackish powder no, but its more likely dirt than that theyhave blown, could try getting them replaced but its a long shot and they probably wouldnt be the only thing damaged, if it is 64bit i cant help ive only got 32bit.

__________________
Q6600-P5K Premium+Alphacool w/blocks
EVGA 8800gt+Koolance w/block
Samsung f1 raid0 +f2 hard drives
Enermax infinity 650w

Popeye67's Blog