SOLUTION: Samsung Galaxy S4 no audio sound during phone call. For me it was a bad SIM Card Reader or Module IF. But it could be a bad SIM card so try a new SIM card before doing this repair or at least take it out and in. My Service Repair Statement said it replaced two things: Part Number Description GH59-13279A Unit-SIM SD SOCKET; SGH-I377, 10-0013-0278 GH59-13111A MODULE-IF SUB FPCB(SGH-I337);SGH-I337,10 Called 800-726-7864 told them what the symptoms were and that the support line said it was the SIM Card Reader and they gave me a quote of $70.36 and seemed confident that the phone would be fixed. Sent to Samsung Repair Facility in Texas, total cost $70.36, and was without it for 9 days. It’s been working for 2 weeks now with no problems. First I took it to an AT&T Service Center and all they really did was try a new SIM Card, next called Samsung Service 888-987-4357 and went thru a series of tests and they said it was a bad SIM card reader and gave me the repair center number. Symptoms: No audio /...