What can clap when you turn on the PC?

Question

Iron

When you turn on the PC, or rather, at the moment it is connected to the electrical network, some kind of quiet, barely noticeable sound is heard in the system unit. As if something inside turned on, I can’t describe it more precisely.
From time to time when applying voltage, I hear loud pops. I don't know where exactly in the system. This has been happening for two years now. What is it clapping? Power Supply? But then why hasn't it burned down yet?

Answer 1

change the power supply 99% that's it.

Answer 2

A quiet sound is very often emitted by low-quality chokes on the motherboard. Well, it would not hurt to throw another power supply ..