My first PC build will not POST after trying for 3 months now. I tried replacing the motherboard before bread-boarding with a friend's parts with similar specs. I found that after using all of my parts with his GPU, the system POSTed. I had a PowerColor Red Devil RX 580 8GB at the time, and the system POSTed using my friend's GTX 980. Therefore, I filed an RMA for the GPU and bought an MSI Gaming X RX 580 8GB. The system will still not POST, and I am on my second GPU. Is it possible that I received another defective GPU or is there something else going on that would cause an NVIDIA card to work but not AMD? My specs are: Ryzen 5 1600x, G Skill Ripjaws V DDR4 RAM 2800 MHz, ASRock AB350M Pro4 motherboard, BeQuiet Pure Rock Slim cooler, and EVGA 600W power supply (my friend has a 550W power supply and Red Devil card did not work with his system either).