I have a late 2012 iMac, 27". I'm very satisfied with it. However there is one problem I do not understand; when I open certain software, usually those that take up a significant portion of the screen, I hear a high-pitched sound coming from the computer. Volume or lighting level does not matter, it is not dependent on anything that I can determine except for the fact that if you select another window so that the offending software (Kindle being a typical example) is not active then the noise disappears immediately. it return immediately if I put the window back into focus.
Where is the noise coming from and how can I stop it?
Where is the noise coming from and how can I stop it?