How do you fix a PC that will not turn on?
Reviewed by Hritik, White Fortress Academy · last reviewed 2026-11-11
Start with power and work inward: check the wall socket, the cable and the power supply switch, then disconnect extras, reseat the memory and test the monitor cable. Most no-power faults are a cable, a switch or a loose part, not a dead computer.
Fix order
- Check the socket and cable: try another device in the same socket, or another power cable.
- Make sure the power supply switch at the back of the case is on.
- Look for signs of life such as fans, lights or beeps. Nothing at all points to power. Lights but no picture points to the monitor or memory.
- Check the monitor cable and the monitor’s input setting.
- Unplug USB drives and other extras, then try again.
- Switch off and unplug the PC, then reseat the memory modules.
- If it still fails, suspect the power supply or motherboard and ask a technician.
Common mistakes
- Replacing parts before checking the socket and cable.
- Changing several things at once, so you never learn what fixed it.
Questions people ask
What if the fans spin but there is no picture?
Check the monitor cable and input first, then reseat the memory and the graphics card.
How do I know if it is the power supply?
If nothing happens at all, with no fans and no lights, even with a good cable and socket, the power supply is a likely cause. Trying a known-good one confirms it.
Also in the arcade: Troubleshoot It! · Hardware Builder, a build-a-PC game for learning computer parts. Terms: psu power supply, ram. All quick answers · IT glossary
Plain-English guide by White Fortress Academy.