My CyberPowerPC C Series desktop has a GeForce RTX 3050, 32GB of RAM, and additional storage. It worked normally while I was gaming last night, but today it will not start at all. When I turn on the switch on the back of the power supply, the case RGB lights come on, but pressing the front power button produces no response—no fans, display, keyboard lights, beeps, or diagnostic LEDs.
I have already reseated the RAM, tried using one stick at a time, checked the cables, inspected the front-panel power button, and reseated the CPU. I also unplugged the external devices. I found suggestions to test the power supply with a paper clip, but I am not comfortable doing that. The motherboard appears to be labeled B560M-C. What would be the safest next steps to determine whether the problem is the power button, motherboard, or power supply?
3 Answers
The B560M-C board may have diagnostic LEDs, so check the motherboard itself while the rear PSU switch is on. If there are no standby lights, the power supply could be failing despite the RGB receiving some power. If there are standby lights but the board never reacts to the power signal, the motherboard or case switch becomes more likely. A known-good compatible PSU is a safer confirmation method than randomly shorting PSU pins; a multimeter or repair shop can also test the PSU properly.
Since the system has standby power for the RGB but does absolutely nothing when the button is pressed, the front-panel power switch or its connection is worth checking first. With the PC unplugged, locate the two small power-switch pins on the motherboard and verify that the connector is attached to the correct pins. Briefly bridging those two pins with a screwdriver can test the switch, but only do this if you can identify the pins confidently. If it starts, the case button or its cable is the likely failure.
You can also try clearing the CMOS. Turn off and unplug the PSU, hold the case power button for several seconds to discharge the system, then remove the CMOS battery for a few minutes before reinstalling it and trying again. While doing that, inspect for a loose 24-pin motherboard cable, a loose CPU power connector near the processor, or any pinched wires. If clearing the CMOS and bypassing the case switch do not help, testing with a known-good PSU or having a technician test the board and PSU is the next practical step.
I checked closely and still cannot find any diagnostic lights or hear any beeps. The RGB is the only thing that comes on, and the power button remains completely unresponsive.