Monitor goes black after second HHD

[ma21212]

Hi, I just installed a second 640GB WD Caviar black hard drive in my system and when I turend it on, it didnt read from my original HHD and told me "Reboot and select proper boot device or insert boot media in...". So I unpluged my new Hard Drive and when I restarted the computer, it ran like normal, reading what I had on my original Hard Drive and I got to my Desktop no problem, but after a minute the monitor went to sleep (but computer was still on). This even happend when I was in BIOS and also when I was on the little OS system that my moboard has on it.

help.... me out plz.....

why does the screen keep going black.

specs:
Windows 7
Asus P6X58D-E
I-7 930
ATI 5870
6GB Corsair Dominator

 

[bavman]

The reason you got that first error message i would guess because your bios was trying to boot from the new drive with no os on it. As for the monitor issue thats odd.