I have got a MBA M1 base variant and am in India with 220 V @ 50 Hz power supply. Currently, my MBA is plugged in (and 100% charged) and through my earphones I am hearing a buzzing sound. If I turn off the power then the sound vanishes.
More interestingly though, if I touch my hand to any area on the metal surface the sound vanishes. Likewise, if the power is plugged-in and I drag my hand through any area of the metal surface then there is a distinctive vibration I can feel which is absent when my hand is resting.
Is this normal behaviour? Is there any chance of damage of any kind? Could this be a grounding issue? I'm pretty sure that the power is grounded (but not 100% sure).
Edit : Additional Comment –
In case it's relevant I bought the MacBook through official online store of Apple so no chance of a run-in with power rating issues. Also, the power supply at my place is rock-steady.
Best Answer
Sounds like an earthing issue. If power supply & mains plug and socket are all correctly earthed, this should lessen or disappear.
Some PSUs aren't earthed - this I've always considered a manufacturer failing.
Technically it's not 'dangerous' as the mains leakage from a switch-mode power suppy is a known quantity, but it does upset people.