I replaced my RTX 3070 with a 9060 XT, and afterward the computer stopped posting. The CPU, DRAM, and VGA debug lights cycle repeatedly, while the RGB lighting and fans work normally. I reinstalled the 3070, but the system behaves the same way, and it also gets stuck in the same loop with no graphics card installed. I have reseated the components, tried one RAM stick, reset the CMOS, removed both M.2 drives, and tested the motherboard outside the case with no peripherals connected. The system has a Ryzen 7 3700X, an ASUS TUF X570-Plus WiFi motherboard, and a 650W power supply. What should I check next?
4 Answers
Some X570 boards can have compatibility or firmware issues with newer graphics cards, and trying the secondary PCIe slot or updating the BIOS can sometimes help. However, because the original card now fails too and the machine won’t post without any GPU, BIOS graphics settings and drivers are unlikely to be the main cause. A PSU or motherboard fault is more likely.
Inspect the PCIe slot and the area around it for damage, debris, or anything that may have shifted while swapping cards. Also check that the CPU power connector is fully seated. The broken retention clip by itself usually shouldn’t prevent posting, but a damaged slot or board could. If another PSU doesn’t help, testing with another compatible CPU or RAM kit may be necessary.
Since the problem remains with either graphics card—and even with no graphics card installed—it probably isn’t a GPU or driver issue. Try a complete CMOS reset by removing the battery for several minutes with the power disconnected, then test with only the CPU, cooler, one RAM stick, and power connections attached. If possible, test with a known-good PSU as well.
At this point I’d focus on the PSU, motherboard, or a loose power connection rather than the graphics card. Reseat the 24-pin motherboard cable, the CPU EPS cable, and all modular connections at the PSU if applicable. Testing with your friend’s PSU is a good next step, provided it has the proper cables and enough power.
I’m going to try a known-good PSU tomorrow. Hopefully that identifies the problem without needing to replace the motherboard.

I already reset the CMOS and tested the system outside the case with one RAM stick, no drives, no GPU, and no peripherals, but it still cycles through the debug lights.