Hey I have a Droid Razr M and I got it around December. It was working fine but then the JellyBean update came and that's when things started to go wrong. At first my phone would receive and make calls but then I would hear a static sound. I would shake the phone or I would put it on speaker and then I would be able to hear the other person and they would hear me.
For the past couple months though I have been getting calls but the person on the other line cannot hear me. I have tried everything from a soft reboot to restoring the phone to factory settings. I have deleted and reinstalled my apps one by one but have had no success. Just today I have tried to clear the cache partition. Nothing has worked and I don't know what else to try. I feel like I've done everything in my power and I don't know what else to do. Any and all help would be greatly appreciated.
If you are having just problems with the Voice capability of your device and other functions are working properly (i.e. texting and browsing) then chances are you need a new SIM card, you may visit a direct VZW store to get a new one for free.