Whining noise from Switch Dock

[MonsterHunter280]

I got my Switch on Friday and I've just noticed that the dock is making a horrid whining noise when the Switch is plugged in. Oddly enough this whine stops when the top USB port on the side is charging something (like my phone). Could this be an issue with the power supply or with the dock itself?

Many Thanks for any help

 

EDIT: So the USB thing was probably incorrect; it still whines regardless

[KZed]

Okay, My switch is about 3.5yo and it's been making a whining noise like this from the fan, for about 1.5 years, no idea why a new one would be doing it. Sorry for the 'no answer' but hope this helps!