List all componets.(I know what you listed already, Name everything)
List Power supply specifications.
Clear CMOS by first removing the AC cord from power supply then locate the small watch like battery on the motherboard, remove it for 3 minutes, then Dissconnect everything from video card Except CPU, RAM and motherboard. Replace AC cord itno power supply and turn it on. If you hear 1 small short beep it means POST was successful and after which you should get a non/no boot device error. You can then turn computer off and add 1 item at a time to the motherboard, turning it on and testing for each item.
If POST is not passed with only Video card, CPU and RAM attached then Reseat RAM and Video card, make sure CPU and heatsink are properly seated. Try 1 RAM stick at a time alternativily.