i have the same problem with my one , first in android 4.3 starting auto-restart and then after a flashing 4.4.2(4.19.401.9) the signal is out of range and imei and base band are unkonwn
i update to 4.19.401.11 and didn't change after all
i really confused , please help me , my hboot is 1.56 and i didn't s-off or unlock yet