Originally Posted by backside floaters
Started a couple days ago, using straight talk AT&T sim on my nexus 5, Data and text messages work fine, but whenever I try and make a phone call the signal drops completely and calls won't connect. People been telling me when they try to call it goes straight to voicemail. I'm running stock rom. Any suggestions? Straight talk and Google both with no help.
I just had this almost exact same scenario. I started having problems with signal dropping using CM12 nightlies (late April 2015) then eventually I switched over to a NET10 because T mobile was not cutting it to begin with. After the problem persisted on an ATT Sim card with NET10, I started flashing different ROMs. Signal seemed to be more stable and everything was fine for a while. After a few days I was no longer able to make or receive calls.
Eventually I did a complete factory image (still didn't work)
Flashed a 4.4 radio image (didn't work immediately, but the next morning it seems to be working as of now)
I probably could have skipped the hours of trouble shooting if I would have (found this thread first) and just tried flashing different radio images. Or maybe it was the series of other steps combined...not really sure.
Good luck and hopefully this helps the next person going through this mess. Oh and don't event waste your time calling NET10/Straighttalk customer service.