Whenever I turn on my PC, the power supply fan makes a loud grinding or rattling noise for about five minutes. It gradually becomes quieter, but I can still hear a faint grinding sound for another few minutes before it eventually stops. The power supply was obtained secondhand several years ago and has only been used for around six months. What could be causing the noise, and is it safe to keep using it for now?
2 Answers
If it’s still covered by a warranty, arrange a replacement instead of opening it. Since yours was obtained secondhand and is several years old, it probably won’t have useful coverage. There’s no reliable way to predict how long the fan or PSU will continue working; it might run for months, or the fan could seize soon. If the fan stops, the PSU may overheat, shut down, or potentially damage other components, so avoid stressing the system and plan to replace it as soon as you can.
That usually means the fan bearing is worn out or drying up. Since the fan is inside the power supply, replacing it yourself isn’t recommended—the unit can retain a dangerous charge even after being unplugged. The safest option is to replace the PSU, or have it serviced by someone qualified.

It was given to me secondhand and has only been in use for about six months, so I don’t think I have any warranty coverage. I’ll avoid opening it and start looking for a replacement.