What may be causing high-pitched noise from computer case?

Question

I've got a custom-built Ryzen 5 PC in a Rosewill Micro-ATX case that a roommate built for me a couple of years ago. It has two hard drives and two SSDs, but no video card. Recently it's been producing a very high pitched tone that I can't figure out what it may be caused by. Today I pointed a condenser microphone at it and opened a spectrum analyzer showing the tone is in the 12khz range.I've turned off speakers and monitors in the past thinking that's where the tone is coming from, but it's from the PC. There is fan noise and hard drive noise that are much lower pitched and easier to identify, but this high pitched tone is very persistent and infuriating and not obviously from fans or drives. What else may it be?

detaro · Accepted Answer

coil whine (or capacitor whine) from some power conversion circuit. GPUs are most famous for it, but the motherboard or the PSU can have it too.

nacho-daddy · Answer

To answer your unasked question,&rdquo;How can I make it stop?&rdquo; :Isolate it with a stick. Put one end on your ear, the other on various components that may be the source of your tone. When you have isolated the component, glue it down to dampen the electromechanical vibrations. Unless it&rsquo;s the power supply. Don&rsquo;t glue that down.