Unusual buzzing sound occurs on PC after power-off.
Unusual buzzing sound occurs on PC after power-off.
Your computer begins to make strange crackling sounds when you shut it down after about ten seconds. After turning off the power button on the PSU, the noise disappears. This suggests a possible issue with your power supply unit or a lack of proper grounding in your home. You mentioned your house doesn’t have grounding, which aligns with the shock you felt when touching cables. The specs you provided indicate a recent update and a specific PSU model.
It could be the fan blades sag at lower spinning velocity and are brushing stuff below it, that's what it sounds like to me. Depending on how long you've had it that should be covered under warranty. A pretty common issue with that PSU in specific and the Coolermaster MWE series is coil whine. It's not dangerous but I don't think it's that because the noise is too deep and spaced out, also you said it happens 10 seconds after shutdown whereas coil whine happens under load. If it is the fan that frictions will shorten the life of your PSU, id recommend just get another one since they're not expensive. YT video of coil whine New 750w PSU
I believed this PSU would perform well. I checked the PSU tier list and purchased it just a year ago. Updated on October 15, 2024 by Irafli Correction.
There are alternative choices for more affordable PSUs that still offer solid performance.