Home Built Desktop, no Video, all lights come on on the MoBo, Fans Spin

[kegerator]

I have tried replacing the MoBo battery, Graphic card, and tested the HDD.
When I reseat the 2 sticks of 4GB RAM it does not work. When I pull one of them out(does not matter which one. I have tried both individually in the first and second slot) I will boot and reboot just fine. After leaving the computer turned off overnight (with only the one stick inserted) it again will have no video displayed. If I reseat the RAM(again only one stick) it will boot and reboot just fine. Is my MoBo defective?

 

[Tradesman1]

What mobo/CPU, sounds like possibly bent pins in socket (Intel) or CPU (AMD)