No video output from GPU

[pcproblemguy]

My computer blew up a couple weeks ago, It's had a new PSU in it, new Motherboard, New CPU, and a new GPU and after trying to turn it on tongiht nothing would show on the monitor, we tried 2 different GPUs that worked prior in different machines and none would work.. unless i have bought a faulty motherboard I have no idea what else it could be. Any help?

 

[popatim]

If you are not hearing the windows startup sound when you boot the computer then you probably have an issue which is preventing the pc from even starting, hence the no-display condition. This condition could be caused by any of the components. Could you list your systems specs with make and model#'s of the parts.
Does it beep?

 

[pcproblemguy]

It doesn't beep and we hear no windows start up sound either, but it seems like it's running.
CPU - AMD FX 6300 3.5ghz
PSU - Corsair CX500
GPU (for now) - Radeon HD 6650 (probably a 1gb) we also tried an older asus GPU that worked prior, still didn't show anything
Motherboard - GIGABYTE GA-78LMT-USB3
1TB HDD

 

[pcproblemguy]

also 16gb of RAM, ( dunno how fast/mhz)