my carrier identity wouldn't even show on the main screen , but could if I swiped down to reveal the hidden backscreen showing wifi,gps carrier etc. first, i did a factory reset, then loaded up all my old apps(that took several hours on 4g) and still the same, nobody can hear me and I can't hear them calling problem /phone freeze/black screen etc. after doing all the research of why this would happen, I went to the google play store to find out which of the 89 apps I've installed had " phone and sms" permissions. I deleated the phone apps that had "phone permissions" except for the kitkat 4.4.2 built in "lookout" app that has phone permissions for your security reasons. calling got better but there was still instances where I couldn't complete the call. I then took out my sim card and cleaned it with hydrogen peroxide, while being careful to use a clean cloth and to let the sim card dry before reinserting it while being very sure that the sim was inserted fully and evenly, which is hard to visualize because the housing slot for the sim is not square. I found my yoda and made the sim seat at 90 degree/and inserted battery. calling got 97% better! but still a wait glitch. I now need to go back thru my apps that have sms permissions and decide which ones I want to keep. I downloaded 89 apps but only use 12. who would of figured?