Hey everyone, I'm in a bit of a jam with my PC and could really use some advice. I'm comfortable with basic troubleshooting and have upgraded systems before, but this issue has me stumped. Here's the situation: My PC turns on – the fans spin, and the lights come on. However, the moment I connect my graphics card with the 8-pin power cable, my keyboard stops responding, and it seems to fail the Power-On Self Test (POST). Without the GPU installed, or even when it's in the PCIe slot without power, the keyboard works fine. I've already reseated the GPU and RAM, cleared the CMOS, checked all power connections, and even tested with a different GPU and PSU, but nothing has changed. I haven't tried switching out the CPU or motherboard yet. Since the failure occurs only when the GPU is drawing power, I'm wondering if it's more of a motherboard or power issue, or if there's something else I should check first. Here are my specs: CPU: Ryzen 3 1200, GPU: Radeon R7 470 Gaming X 4GB, MOBO: MSI A320M-A PRO, RAM: 8GB DDR4 3600MHz Crucial Ballistix, and PSU: Seasonic Focus GX-550 80+ Gold.
2 Answers
It sounds like you might be dealing with hardware failure, considering the age of your PC. If it's ten years old, it could just be time for an upgrade. But since you got it for free, it might be worth investigating.
It could be the graphics card or motherboard causing the issue. Your motherboard only has one full-length PCIe slot, so without another compatible GPU for testing, it's hard to determine the exact culprit. But if the GPU works in a different system, that suggests the motherboard might be the problem.
I know the GPU is good because I tested it elsewhere, which is making this even more frustrating.

I got the PC for free too, so I’m just trying to figure out if it’s salvageable before investing in anything new.