Studio 540 - "Missing Operating System"

Dell Studio 540 - Windows Vista Ultimate x64

I recently experienced a hardware issue with my desktop. Dell dispatched a technician who was able to resolve the hardware issue by replacing the motherboard, cpu and power supply. It appears the CPU was the culprit behind the original hardware issue. However, now my desktop won't boot. It's as if the hard drives are unrecognized. I see the message "Missing Operating System". I loaded the original OS disk that came with the desktop. It sees the C: partition as unformatted.

Desktop is configured with two 640GB Samsung SATA drives in a RAID 0 config. From what I can tell, the drives are plugged in correctly. The only configuration options in the BIOS are "ATA" or "RAID" for the onboard peripheral devices. I can choose RAID, save changes and exit, yet it still won't boot. Going back into the BIOS, the same option is set back to ATA. This is an integrated RAID controller, and I see the same symptoms using the original motherboard and the replacement motherboard. The PC does initiate one beep, followed by 3 quick beeps during post.

I can't help but think there should be additional RAID configuration options, but none are to be found. Are there any tips and/or tricks I'm missing, or is it likely the original CPU problem has somehow caused this additional issue?

If there doesn't appear to be any solutions, is anyone familiar with an external SATA drive bay I can plug these drives into and then access from another PC via USB?