My PC randomly powers off while I'm playing games such as Marvel Rivals, Minecraft, and VRChat. There's no warning or blue screen—it simply loses power. All of the fans appear to be working, but I'm not very experienced with PC troubleshooting and suspect the CPU might be overheating. The shutdown can happen within the first hour, after playing for a while, or not happen at all. The computer is more than five years old, although I did upgrade the graphics card at some point. What should I check first?
4 Answers
Work through the basics before changing clock speeds: clean dust from the heatsinks and filters, make sure the case has both intake and exhaust airflow, reseat the GPU and its power connectors, and reset BIOS settings if you have changed any overclocking or voltage options. If temperatures look normal, test the CPU, GPU, and memory separately with reputable stress tests. If only combined CPU-and-GPU load causes the shutdown, the PSU becomes especially suspicious.
Start by monitoring your CPU and GPU temperatures while gaming with a hardware monitor. If either temperature climbs too high right before the shutdown, clean out the dust, confirm the fans are responding to temperature changes, and check that the CPU cooler is mounted properly. Replacing old thermal paste may also help, but temperatures should be measured before changing anything.
Check Windows Event Viewer after the next shutdown under Windows Logs > System. Events such as unexpected shutdown or Kernel-Power can confirm that the system lost power, although they usually won’t identify the exact failed component. Thermal-related events may provide more evidence, so compare the event time with your temperature readings.
A complete instant power-off often points to the power-delivery system rather than a normal software crash. Since the graphics card was upgraded, check whether the power supply has enough wattage and whether its cables are firmly connected and undamaged. An aging or undersized PSU can shut down when the CPU and GPU suddenly demand more power. Avoid continuing to use it if you find melted, discolored, or overheated connectors.
The PC is over five years old, and the graphics card was upgraded later. The shutdowns don’t always happen immediately, so I’ll check the power supply model, wattage, and cables first.