Nano 2G heat sink appears to vibrate / resonate, is this normal?

With my hand touching the heat sink after powering on the 2G, i can feel it is vibrating very lightly, with a standard rhythm. It is like resonating. Is this normal?

I am using a Raspberry 4 official power supply unit (5.1V 3A). Thanks in advance.

Hi, can you share the photo of it?

The vibration is not visible but i can feel it with my hand.

There is no vibrator components on board… did you touch the big capacitors? The only reason I can imagine is charging/discharging of the big capacitors. You can try another power supply with more powerful output capability.

thanks but no i’m touching the big heat sink. just tried to touch the capacitor but no it’s normal no vibration.
it’s the official power supply unit i’m using so just curious of the vibration as obviously there’s no moving part like fan.

No clue on this… is it possible to remove the heat sink to check if any component on module is vibrating? Is there any abnormal performance during using it?

Apart from the vibration the unit functioned perfectly. My only concern on this is safety. Thanks for all your help.