Apple has confirmed it’s aware of a known issue with the microphones on some iPhone 7 and 7 Plus models running iOS 11.3 or later.
Reportedly, the bug may cause issues with users being heard in phone calls or FaceTime calls after installing iOS 11.3 on iPhone 7 devices. Additionally, it can also affect speakerphone functionality — resulting in a grayed-out speaker button on the iPhone’s display.
The Cupertino tech giant sent an internal support document to Authorized Service Providers guiding repair staff through how to diagnose the issue.
Repair staff are instructed to disconnect any audio accessories from impacted iPhones. Apparently, this can alleviate some of the reported cases of this problem (in other words, you should try this at home if your iPhone 7 or 7 Plus is acting weird in calls).
If the speaker button remains grayed-out, diagnostics can be run. An affected device may display a “device could not detect dock” or “accessory not supported” alerts. Once technicians spot the problem, they can carry out the appropriate repairs.
It’s worth noting that Apple is instructing repair technicians to make an exception for devices with this issue if they are out-of-warranty. While we can’t confirm that the repairs will be free (the document doesn’t specify), it seems likely.
The issue doesn’t seem particularly widespread, but a number of complaints have surfaced on various support forums and social media sites such as Reddit and Twitter. It’s not readily clear what’s causing the issue or how many total devices and users it is affecting, but it’s worth venturing that something within the iOS 11.3 update could be causing hardware-based problems.
Apple has yet to publicly acknowledge the bug, but the fact that it sent out an internal service document confirms that it’s a known issue with an avenue of repair.
How to Troubleshoot Microphone Issues
As stated earlier, if you’re experiencing microphone issues on your own device, try disconnecting any Bluetooth audio accessories.
If the issue persists, you should set up an appointment at a Genius Bar or an Apple Authorized Service Provider.
Go to this page, select iPhone > Repairs & Physical Damage > Unable to Hear Through Receiver or Speakers > Built-in Speaker > Bring In For Repair.