オリジナル投稿者： Minho ,
The iPhone 7 series of devices suffers from issues with the Baseband IC, Audio IC and weak traces on the pcb which crack and break. It is a similar design flaw to the iPhone 6 Plus, known as [https://www.refectio.ca/blog/touch-disease|Touch Disease]. On the iPhone 7 series, the weak traces are underneath the Audio IC. In many cases an internal short within the Baseband IC causes the boot looping, which unfortunately, is not repairable because the Baseband is code locked to the logic board. It can also be caused by a broken trace underneath the Audio IC. Replacing the Audio IC and strengthening the weak trace with a micro-jumper can repair this. If you are curious about the technical nature of these failures, you can listen to this video from [https://www.youtube.com/watch?v=kHRfpHa4AZs&t=8261s|Jessa] and this one from [https://www.youtube.com/watch?v=gXXNPqthfU4|Jason] at STS, they go into a lot of detail regarding this issue. It could be BB or Audio but the info in the video should help you figure out which one.