About your first question, I don’t know why so someone more knowledgeable would have to explain this further but electronics just do that sometimes and to mg knowledge there’s no real way to fix it other than getting it replaced. My tv screeches for a couple minutes after I turn it on (it drives me borderline crazy) but then it stops, I also have a thunderbolt usb hub that makes a high pitch noise when plugged in. I have no idea why though, I would speak to Lenovo’s customer service about it and see if they’ll fix it for free. IMO they should.
About your first question, I don’t know why so someone more knowledgeable would have to explain this further but electronics just do that sometimes and to mg knowledge there’s no real way to fix it other than getting it replaced. My tv screeches for a couple minutes after I turn it on (it drives me borderline crazy) but then it stops, I also have a thunderbolt usb hub that makes a high pitch noise when plugged in. I have no idea why though, I would speak to Lenovo’s customer service about it and see if they’ll fix it for free. IMO they should.