caller cannot hear my voice unless using earphone

Solution
Try recording your voice and see if it works. Not with the phone app, but another app. If it does then the microphone is working. You will then need to check your settings in the phone app to make sure it isn't muting you.

If, however, you can't hear anything you try to record, then you may need to have the device looked at and the mic replaced.
Try recording your voice and see if it works. Not with the phone app, but another app. If it does then the microphone is working. You will then need to check your settings in the phone app to make sure it isn't muting you.

If, however, you can't hear anything you try to record, then you may need to have the device looked at and the mic replaced.
 
Solution