system not coming on.
 

i was about to continue a video edit i was on and when i put my system on,after booting it showed a message that one of my hardrives was missing which is striped in a raid 0 with 2 WD black caviar hardrives.tried troubleshooting to no avail.now my system doesnt even come on anymore.thought it was my psu but it has been checked that its fine.please what could be the problem?
this is my pc spec>.
ASUS P6X58D-E LGA 1366 intel X58 SATA 6GB/S USB 3.0
INTEL QUAD CORE i7 950
CORSAIR XMS3 12GB[6*2GB]DDR3 1600{PC3 12800}
ANTEC NINE HUNDRED TWO BLACK ATX CASE/
WD VELOCIRAPTOR 150GB
CORSAIR CMPSU-850TX 850W ATX12V 2.2 /EPS12V 2.91 SLI ready crossfire
GTX 470
2 x WD Black Caviar 1 TB 7200RPM SATA 6.0Gb/s 3.5 internal harddrive
Coolermaster V8 CPU cooling fan
windows 7 home