I have had a Galaxy S4 mobile phone (GT-i9505) for years and have had no problems with it. My wife wanted a phone so I purchased a new S4, same model, and purchased a pre-paid sim and SD card. I set it up similar to mine and was going ok for a couple of weeks but now has a fault.
When she calls anyone their phone rings but when they answer it is dead, no sound, also if anyone phones her and she answers it is dead!!
What is strange is that she can SMS with no problems, also data works fine, it is only voice phone calls.
Anyone have any ideas?
PS. I know this is a way out question for Subsim readers but I have been stumped by this for days now.