Question System Won't Boot

[Alex.D1]

I recently got an ASRock RX 6900 XT. When I plug it in, the pc won't boot. I have changed nothing except for the graphics card. I think it may be my motherboard or power supply, but I'm not very knowledgeable when it comes to pc components and troubleshooting. I put my brothers gpu, which I know works, into the pc and it didn't boot that time as well. The only way to get it to boot is to not have a gpu plugged in. It can be mounted on the motherboard, but the second I put the pcie cables into it, it won't boot. I don't think that the card is dead beacuse I put it into another machine and it booted; however, only 2 of the 3 pcie slots were plugged in, so nothing showed up on the screen. I can't use the on board graphics to check anything in the bios either. It just says there is no connection on my monitor even though it is powered up and seems to be running.

motherboard: MSI B550 GAMING EDGE WIFI
cpu: RYZEN 5 5600x
gpu: ASROCK RX 6900 XT
ram: T-FORCE 32gb
psu: SEASONIC FOCUS GM-750

 

[DRagor]

Most likely PSU detects a short on PCIe. Since it happens on two GPUs I would assume the problem lies in the cable (or PSU) itself, not in either of GPUs. If your PSU have more PCIe cables check them out, also you can check other 8-pin ports at PSU side if it has more then three.

 

[Alex.D1]

Most likely PSU detects a short on PCIe. Since it happens on two GPUs I would assume the problem lies in the cable (or PSU) itself, not in either of GPUs. If your PSU have more PCIe cables check them out, also you can check other 8-pin ports at PSU side if it has more then three.

No if all three are plugged in it doesn't work. If only one is plugged in it doesn't work. If none are plugged in, it works. What you are referring to is the fact that I put it in my brothers machine and only plugged in two just because I wanted to test if it booted up, which it did. I have all three in on my personal machine, which is the one having problems.