My PC began randomly shutting down or restarting a few days ago, sometimes showing Kernel-Power Event ID 41 in Event Viewer. Now it powers on but does not complete POST or produce an image. The CPU and case fans spin, while the GPU fans do not. The keyboard does not respond to Caps Lock, and none of the MSI EZ Debug LEDs light up. The monitor wakes when the PC starts, but remains blank. The physical power button also stopped responding, so I had to switch off the PSU.
I have already reset the CMOS, tested both RAM sticks individually and one stick in the A2 slot, reseated the GPU, disconnected the SSD and other peripherals, and tried a minimal setup. I also tested with the RAM and GPU removed, but the fans still spun without any EZ Debug LEDs lighting. The GPU's red power indicator turns off when its PCIe power cable is connected.
The system uses a Ryzen 5 5500, XFX Radeon RX 6700 XT, MSI B450M-A PRO MAX, Corsair CV650 PSU, and 16GB of T-Force Vulcan Z DDR4. The crashes occurred during normal or idle use, not just under heavy load. I do not have spare parts available for swap testing. What should I test next, and could the PSU or motherboard be failing even though the fans and lighting still receive power?
1 Answer
Fast Boot is a Windows or firmware convenience setting and will not help when the system cannot even reach POST or respond to Caps Lock. At this point, the most useful test is to strip the system down to the motherboard, CPU with cooler, one RAM stick, PSU, and—because the Ryzen 5 5500 has no integrated graphics—the GPU. Disconnect storage, front-panel USB, and all unnecessary devices. Clear CMOS properly, then try the other RAM stick and inspect the CPU socket, motherboard, GPU slot, and power connectors for damage or looseness.
Fans and RGB only prove that some power rails are present; they do not prove that the PSU can provide stable power under startup or load. Given the earlier sudden restarts and the failure of the power button to shut the machine down, the PSU is a strong suspect, although the motherboard could also be defective. The best next step is testing with a known-good compatible PSU, followed by testing the GPU in another system or using a known-good GPU. If the machine still cannot POST with a confirmed-good PSU and GPU, the motherboard becomes the likely failure.
Fast Boot is already disabled, and the system currently has no display at all, so I cannot change that setting or get into firmware.