Surface Dock Makes High Pitch Sound....

[paulektaylor]

When I have multiple USB ports being used... I haven't attempted a 2nd or third display, but just from an external HD (seagate 4TB slim portable) and a couple of other usb devices it makes this awful high pitch sound. It's almost not noticeable until you are right next to it, but now, when I'm at my desk, I can't not hear it... What's worse is the Dock Updater app doesn't see my dock, but my SB registers everything...

 

[Votality]

Sounds like the power supply in the dock. Often switch mode power supplies can make a slightly audible sound if the switching frequency produces an audible harmonic. Can be due to many reasons one of which can be the capacitors they use. (Some smd ones have a piezo electric effect so they act like a mini speaker)