Raspberry Pi Zero Buzzing/Humming Noise

Hi All,

Since yesterday I have been experiencing the following issue with my beloved Raspberry Pi Zero. Basically as soon as I power up the Pi I can hear some sort of buzzing/humming noise coming from the SoC. I have tried with different power supplies (even with USB power banks) but to no avail. Also this issue occurs with all the USB peripherals detached.

Many thanks for any kind advice or suggestion.