Chosen Solution
My iPhone 7 had water damage a year ago. I dried it out and replaced the digitizer and it has worked fine until yesterday. I tried to answer a call when it rang and it appeared to answer the call but no conversation was allowed, no voice in or out. I tried making a call and it rang on speaker but still no conversation allowed. Everything else seems to work fine. I have not tried Bluetooth though
The iPhone 7 series of devices have proven to be very unreliable, suffering from flex-based issues similar to the iPhone 6 Plus (Touch Disease). On the iPhone 7, the fault line runs along the top of the SIM card reader and affects the Baseband CPU and Audio IC. Any short copper traces running perpendicular to the fault line while connecting to micro-BGA pads, is subject to failing. On the Audio IC, this particularly affects the C12 pad/trace although there are 4 pads/traces along the fault line. Of those four, the C12 pad (I2S_AP_TO_CODEC_MCLK) is the most critical as it is a communication protocol line between the CPU and the Audio IC. ’’’’ Here are the typical symptoms, as collated by the repair community: Voice Memos app / Loudspeaker on call - greyed outSiri doesn’t hear you / Caller can’t hear youMost other Audio related issues that aren’t solved by modular replacementsLong boot times (3-5 minutes)iTunes detects the phone but stuck on the Apple Logo If you have any one of the symptoms above, your device may suffer from this issue. This is a repairable problem but it requires a micro-soldering repair. However, with it’s previous history of water damage, it may also be a latent issue as well.
