Loop disease is caused by a loosening of the audio chip on the motherboard.

Unless you are a tech pro, entrust this issue to the specialists. A fix requires removing the chip and soldering a small section of wire beneath it to repair the connection.

Apple will offer a replacement at the rate of 319$ US.

Tip: find an authorised service provider in your area -> https://locate.apple.com/pr/en/

Wish you good luck with the repairs!