Monitor wont start with more than 4gb Ram!?

[Northern Lightz]

Hi everyone!! I have 4GB ram installed and for some reason i cant install any more than 4GB otherwise the monitor wont turn on? I've tried all the slots to make sure they all work and they do, I've also tried several different ram cards and all the results lead to it not working with more than 4GB ram!!?
ANY suggestions?

Windows 7 64 bit
CPU: amd phenom ii x4
GPU: Radeon hd 7700
MOBO: Gigabyte M720-US3
PSU: Cooler Master Silent Pro Gold 550W

RAM:
Kingston 2 x 2GB ddr2
1.8v
800mhz
5-6-6-18

Kingston 2 x 1GB ddr2
1.8v
800mhz
5-5-5-18

 

[volcanoscout]

Any time you mix sets of RAM, rather than using a matched set, it's possible to get compatibility issues, even if the different sets are identical make, model, speed and timings. What configurations have you tried in the DIMM slots?

 

[Northern Lightz]

I've only ever tried them in pairs according to the color of the slots

 

[volcanoscout]

Try them with one stick from each set in a matched color, but with symmetrical settings. (I.e. Put one of your 5-5-5-18 sticks in slots 1 and 3, going from your CPU, then one each of your 5-6-6-18 sticks in 2 and 4.)

 

[Northern Lightz]

I seriously cant believe that worked!! Thank you so much!!!!!!!

 

[volcanoscout]

De nada.