My CyberPowerPC C Series desktop with a GeForce RTX 3050, 32GB of RAM, and additional storage worked normally while I was gaming last night. Today, flipping the power switch on the back makes the usual RGB lights come on, but pressing the case power button does absolutely nothing—there are no fans, beeps, keyboard lights, or display output. The monitor is a TV, but it has worked fine before.
I've reseated the RAM, tried one stick at a time, reseated the CPU, checked the cables, inspected the front power-button area, and disconnected external devices. I'm not comfortable testing the PSU with a paperclip. The motherboard appears to be a B560M-C, and there are no obvious diagnostic lights or beep codes. What should I check next?
3 Answers
Since the system shows standby RGB, the PSU is at least providing some power, but that doesn’t prove it can start the computer or deliver stable voltages. The paperclip test only checks whether the PSU starts, and it can be risky if you’re not familiar with it. A multimeter or a known-good compatible PSU would provide a more useful test. Also identify the exact motherboard model and check whether it has hidden diagnostic LEDs or beep-code support.
The power button or its small motherboard connector could be the failure. With the PC unplugged, confirm that the front-panel power-switch connector is attached to the correct pins. If you’re comfortable working from the motherboard manual, briefly bridging only the two power-switch pins can test whether the case button is bad. If that still produces no reaction, the problem is more likely the PSU, motherboard, or a power connection such as the 24-pin or CPU power cable.
You can also try clearing the CMOS: shut off the PSU, unplug the computer, hold the case power button for several seconds, then remove the CMOS battery for a few minutes or use the board’s clear-CMOS procedure. Reinstall the battery, reconnect power, and try again. Make sure the 24-pin motherboard connector and the CPU power connector near the processor are fully seated, and check for any pinched wires. If clearing CMOS and verifying the front-panel connector do nothing, testing with a known-good PSU or having a repair shop test the board and PSU is the safest next step.
I checked around the front panel and the cables, but the button remains completely unresponsive. There are also no motherboard lights, flashes, or beeps when I try it.