Apple admitted today that some iPhone 7 and 7 Plus models running iOS 11.3 or later may have an error that deactivates the microphone during phone calls, MacRumors detected through a leaked document. The few users with the affected devices can see the button of their attenuated speakers when making calls or video chat through FaceTime. The problem seems to affect only phones that run that version of iOS or versions after 11.3.
Some users of Reddit and Twitter have reported microphone problems in recent months and the leaked document, sent to their network of authorized Apple providers, apparently confirms that Apple is aware of the problem.
Apple advises these technical support workers to instruct customers to first turn off or turn off Bluetooth devices and accessories that were connected to their iPhones, as a possible solution. If that does not work, it is also recommended that technical support run audio diagnostics, which will show if the iPhone needs repair with warning messages such as "non-compatible accessory" or "the device could not detect the coupling". Once a message like this appears, technical support can begin to fix the iPhone. Apparently it is not clear in the document what is the real problem of the software or hardware, notes MacRumors .
Even if the user does not have a device covered by the warranty, Apple is making an exception and their store employees at the Genius Bar will fix the problem without question. The document apparently does not say if the repair is free. We communicate with Apple to comment.