Just replaced my N4 with another N4 .. the first one had been a work horse but was wearing out with a few issues.... Replaced with another new one ... The old one ran on 5.01 the new one runs on 4.4.4 Wifi is working great.. I set up my APN same as before... The phone wont make calls.... Double triple checked my APN....Turned off the WIFI . No calls.... Need some help.. I'm on straight talk...