My PC was built about two months ago. It starts normally, runs for a few minutes, then the fans suddenly ramp up, the display goes black, and the computer shuts itself off. Could this be caused by overheating, poor airflow, a cooling problem, or possibly the power supply?
4 Answers
Use a hardware monitor such as HWiNFO64 to watch the CPU and GPU temperatures while the computer is running. Also check whether the CPU fan and GPU fans are actually spinning. If temperatures climb unusually high before the shutdown, inspect the cooler mounting, fan connections, case filters, and intake and exhaust airflow.
The fan speed jumping right before shutdown strongly suggests the system may be hitting a temperature limit. Check that the CPU cooler is firmly seated, has good thermal-paste contact, and that any protective film was removed from its base during assembly. A cooler that is loose or still has the plastic attached can cause this even on a very new build.
If the temperatures look normal, the power supply becomes another possibility. A failing or undersized PSU can cause an abrupt black-screen shutdown, especially under load. Check the power connections and, if possible, test with a known-good unit. System logs may show an unexpected-power-loss event, but a sudden hardware shutdown may not leave a useful log.
Make sure the case has a clear front-to-back airflow path. Check that intake and exhaust fans are facing the correct direction, filters are not blocked, and cables are not restricting airflow. Since the system is fairly new, incorrect cooler installation is more likely than a dust buildup problem.
The fans do spin, but they suddenly become extremely loud just before the screen goes black and the PC powers off.