Chosen Solution
I’m working on an iPhone 7 that when the headphone adapter is plugged in the phone does not switch to headphone mode. The Audio IC chip has been replaced, I have tried multiple lightning adapters and different charging ports. Any suggestions?
You may have already done this but you need to insure the charge ports are of “known-good” quality. It can happen to receive a bad batch from suppliers. Assuming you’ve done that, the next thing I would suggest is to insure you have jumpered the C12 pad, even if it looks okay. There are actually four tiny traces along the Audio IC that can be affected by the flexing issue and usually just solidifying C12 is sufficient but there are more and more reports of the second pad also having issues. Finally, sometimes the Audio IC gets damaged during the removal and reball process. If in doubt, try another new IC.
