Extraneous sounds while accessing the HDD. Where?

Question

Iron

There are two hard ones: SSD and HDD.
When accessing the HDD, for example, installing a game or just when working with the browser (the cache is apparently being written), a squeaky-buzzing sound is heard from the system unit. The HDD diode is on - sound appears.
At first I thought that the hard one was dying. Changed. Did not help.
I started to listen, I thought that the PSU was buggy, changed it, and at the same time installed a more powerful one. Did not help.
Now it feels like the sound is coming from the processor. Everything is fine with the cooler, and the speed does not change when accessing the HDD.
Where could this sound come from? I suspect that soon something will be covered, and since. The computer is a means of earning money, I would not want to lose it at the wrong time. It is better to go to the store in advance.
Can the motherboard or the processor itself hum?

Answer 1

Extracting 4096-bit RSA keys using a microphone
In short, the computer always consumes different power. Poorly glued chokes always make a sound. The power consumption changes - the frequency and amplitude of the sound changes. That is what you are hearing.