Forum Discussion

EzraOak's avatar
EzraOak
Iron Contributor
Jul 04, 2025

PC turns on for a second then turns off

So recently I installed Windows on my PC. The installation went well. However, the CPU got to 100°C. That meant the CPU cooler would need to be replaced, so I did it.

When I pressed the power button, the computer turned on, before turning off a second later.

Does anyone know how to fix this?

2 Replies

  • BrantleyFrost's avatar
    BrantleyFrost
    Iron Contributor
    Jul 07, 2025

    If after these steps the PC still won't stay on, consider:

    • Testing with a known-good power supply.
    • Re-seating or replacing the CPU if suspected to be damaged.
    • Consulting a professional technician if hardware issues persist.
  • Olaann's avatar
    Olaann
    Iron Contributor
    Jul 07, 2025

    Double-check the CPU cooler. Make sure it's seated completely and firmly on the CPU. Is the thermal paste applied correctly and evenly? If you didn't get good coverage with thermal paste, that can lead to overheating. A tiny bit of thermal paste is better than none, but too much is a problem too. A little bit of thermal paste is all you need.