I had the same issues with my at&t 1520 a while back, and ended up having to get a warranty replacement... But here's what to try first; reboot the phone (hold power and volume down together for about 10 seconds until it vibrates). If you're still having issues, I'd contact your carrier and see if there's any problems or work being done on the towers in your area. You never know, it could always be on their end.
Next step, would be to activate a new SIM card with your carrier (at&t will do this free, idk about other carriers) If that doesn't improve your connectivity, you might want to try a hard reset. First back everything up so you can restore all your apps and settings etc, then go to settings/about/reset your phone.
Once you've tried rebooting, making sure it's not on your carrier's end, activated a new SIM card, and lastly a hard reset, I'd look into your warranty status, as you may need a replacement. Evidently, as I've found out, the radios/antennas in these phones CAN go bad and become defective. What causes it, I have no idea...
01-27-2015 05:00 PM