Who whistles in the router?

Question

Iron

the whistling sometimes disappears and reappears.
when you hit the router with a thick book about C ++, the whistle changes its tone.
how to treat this ailment, does anyone have a prescription? The router is a pity, although it is quite old.

Answer 1

PWM usually whistles, transformers - probably cannot be cured without a soldering iron.

Answer 2

As an option - change the book to Delphi or JavaScript;)
But seriously - check the power supply of the router. Perhaps the electrolytes have dried up and ripples of the output voltage have appeared, or it has subsided.

Answer 3

This is a daemon that forwards data packets.

Answer 4

There is an option to buy a new router, fortunately, now this is not a problem.

Answer 5

Or a coil (a cylinder with a blue ring) or two identical black barrels at the power connector (it's not clear what this is from the photo). Treat with abundant pouring of hot melt adhesive or epoxy.