Manually enable Dual channel RAM

[steve10765]

So I have been having a problem, http://www.techist.com/forums/f77/8gb-ram-4gb-usable-266900/
(please read OP)
I so my Mobo knows there is 2 sticks of RAM in my system and so does CPUZ. When I looked at CPUZ I noticed that I was no longer in dual channel mode, how do I enable this manually, I am in the right slots, just out of the blue the RAM stopped working. Each RAM stick works and so does the DIMM slots because its detecting it. ( I tried it in different slots anyway, yes I know I cant do dual channel in the other slots)

Also could you take a look at my memory, the serial numbers are different and maybe thats why they are not working.

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I am hoping this is why my RAM is only showing up as 4gb of 8gb usable.
YES - I am in the right slots for dual channel
NOTE - when I go into my bios it says 4096MB OK then in my bios system specs it says I only have that much ram

 

[Joe C]

It only shows slots one and three...it might be that the slots two and four are dead. That's typical for dual chanel mode but you really need to look in the manual of that board to see what slots they are using for dual channel mode. Does the bios show any memory in slots 2 and 4 when it has memory installed in it?

 

[steve10765]

It only shows slots one and three...it might be that the slots two and four are dead. That's typical for dual chanel mode but you really need to look in the manual of that board to see what slots they are using for dual channel mode. Does the bios show any memory in slots 2 and 4 when it has memory installed in it?

OK so My mobo reads when I have RAM in slots 1,2,3, and 4. BUT if I try to start with 1 Ram stick in DIMM 2 my computer wont beep (post) and the same thing happens if I put 1 Ram stick in DIMM 4. The computer will post though if I put that stick in Dimm 1 or Dimm 3.

So i think my mobo can read that I have a RAM stick in, but it cant use it.

Also when I put both stick in DIMM 1 and 2 it will still only read as 4GB ram not 8GB.

ALSO, how do I enable Memory Remapping? I tried to look online but nothing really helped