Answer to: No sound or mic during calls only.The problem for me was in my SD card. I had tried everything before I tried that, and it seemed the more I tried, the worse the problem got. It had been an intermittent problem, so sometimes things would seem to fix it but weren't actually fixing it. I tried: -Restart (no fix) -Restart after removing battery (no fix) -Restart after removing SIM card (no fix but appeared to work at first) -New SIM card (no fix but appeared to work at first) -Phone calls to my service provider (Bell Mobility - Canada) They said contact Samsung -Phone calls to Samsung ... obviously they said contact Bell Mobility -Factory Reset ... numerous times (no fix) -Remove SD Card (fix) -Install new SD Card (still fixed) Somewhere along the line, something was installed on my SD card or some corruption on the card made the phone do this. Although I've likely permanently lost some data, my phone works as a phone again.