Question Help with motherboard boot

[Adamund]

I have a ASUS WSZ390 PRO motherboard with onboard graphics that won't POST with only CPU and 1 stick of RAM on it. I get 1 long beep and 3 short beeps which indicates no VGA detected as well as the VGA led light on. I also get an A2 code. All connectors and plugged in. CPU has block on it with fan and pump cable plugged in.

Any reason anything but the onboard VGA may be the problem?

Thanks,

 

[rgd1101]

full system spec? include make and model of the psu