the system wont boot and ez debug led shows vga error when i try to boot when gpu installed on pcie slot 2 doesnt matter gpu on slot one is populated or not
cpu ryzen 3700x
gpu gtx 1660
ram 16 gb@3600mhz
mobo msi x570 gaming plus
How many GPUs did you use? If you have only one, assuming you can boot the pc with the gtx1660 in pciex16 slot #1, that means the slot #2 may have problem. You should try to update the BIOS, chipset driver first, if you get the same problem, either RMA the MB or just forget about to use the slot @2, because you have only one GPU.