Computer no longer recognizes ram

[Thamuz]

While I was using my computer earlier today it randomly shut off. When it restarted it detected 2gb of ram instead of the usual 6gb. I restarted the computer and the bios detects the ram but when I check system information on boot it says only 2gb. The computer only boots if there is ram in the second black slot out of the 6, 3 black 3 blue, slots. When I put ram only in the 3 blue it beeps 3 times and restarts. When I put ram in the first and second black slot the computer doesn't beep but just keeps restarting.

Any help would be appreciated. I've tried all 3 sticks in the second black slot and they all work

 

[almartin]

I take it you have 3 ram chips of 2 gig each so use only use 2 chips to start with and put them in slot 1 and slot 3 or slot 2 and slot 4 which would be dual channel and then switch 1 chip for the other chip to see which chip is bad.

 

[Emperus]

Please give us your complete system and OS details. Also, mention if you had overclocking employed and/or tweaked any BIOS setting. To check out the memory modules, you can run memtest.