Ursprünglicher Beitrag von: jessabethany ,
iPhone 7 and 7 plus boot looping most common cause in my experience is a fatal one---an internal short within the required baseband CPU---a chip that is unique to each device and cannot be replaced. This fault is characterized by a "baseband style" boot loop that lasts 15-20 seconds. Second most common is audio ic fault---characterized by a long boot loop lasting 3 minutes. There are MANY other causes--bad screen, bad fcam assembly, charger damage, water damage, flash memory corruption etc. If I had a phone with the short bootloop I'd rule out parts and look for a short circuit near BB_CPU. If it was long boot loop I'd send it out for audio ic work.