I can make & receive calls. However, I can't hear the person on the other line unless I turn the speaker on. When I shut the speaker off, it goes back to dead silence. I've already tried some of my own troubleshooting, nothing has worked. I don't know what else to do. And I'm thinking my device is defective now. I also just got this phone about a week ago, so it's brand new.
Try doing a master reset on device if it is just some calls if all calls it maybe the phone is defective and will need to replace. Make sure contacts saved in G-mail or back up assistance before master reset on device.
MasterReset/Soft Reset:Allows to reset device back to factory settings.
Factory Reset option 1 From the main screen, touch menu tab Touch Settings Touch Privacy Touch Factory Data reset Touch Reset Phone Warning: This will erase all data from your phone, including:
Your Google account
System and application data and settings
It will not erase: Current System software and bundled applications; SD Card files, such as music or Photos
Factory Reset option 2 - Warning this will reset device back to original factory settings.
Turn off the phone
Press and hold "home" + "end" + "volume up or down" keys together for a few seconds when the device is power off
Once device displays boot information, release keys.
Soft Reset Press the Power key. Touch Power off. Touch OK. Press the Power key to power on the device.
Remove battery cover, remove battery and reinstall.