My prebuilt gaming PC worked normally yesterday, but today pressing the power button does absolutely nothing—no fans, lights, or other signs of power. I've confirmed that the power strip and outlet work with other devices, and the switch on the back of the power supply is turned on. I also tried unplugging the PC, holding the power button for 30 seconds, reconnecting it, and trying again.
I'm not very familiar with PC components, so I'd appreciate beginner-friendly instructions. There are no visible lights inside the case, and I've checked that the main motherboard power connectors seem firmly attached. What should I safely check next, and how can I tell whether the issue is the case power button, a loose cable, or a failed power supply?
3 Answers
The small front-panel wires are usually connected along the lower edge of the motherboard and control the case’s power button. If that connection has come loose, the computer may appear completely dead even when the power supply is fine. Use the motherboard manual or the PC manufacturer’s diagram to identify the power-switch pins rather than guessing. If you’re not comfortable doing that, a repair technician is the safest option.
Since the outlet and power strip are working, check the power cable at both ends and confirm the switch beside the power supply is set to “I,” not “O.” If there are still no lights or fans, the power supply or the case’s power-button connection becomes more likely. Unplug the computer before opening the side panel, then look for any obviously loose cables—especially the small wires from the front power button and the large power connectors attached to the motherboard. Don’t force any connector that doesn’t fit.
A completely silent, dark system usually points to a power-delivery problem rather than Windows or the graphics card. Check whether the power cord or any modular power-supply cable is loose, and look for damage or a burning smell. Avoid opening the power supply itself or performing a paperclip test unless you fully understand the risks; a faulty PSU should be replaced or tested by someone qualified. If the external checks pass, the likely causes are the PSU, the case power switch, or a motherboard connection.
One cable underneath the power supply looks a little loose, although I can’t get it to plug in anywhere. I’ll avoid forcing it and focus on checking the clearly labeled connections.
I checked the power-strip setup and the switch, and both seem fine. There are no lights inside the case, but the motherboard and other cables look connected.