Last month my Android 4.4.4 Moto X 1st Gen with only OTA updates received a "No mobile network available" prompt when trying to make/receive calls. This was right after an OTA update. 4G LTE Data worked (maybe all available bands can access data, I'm not entirely sure). I decided to upgrade to 5.1 using this guide
http://forum.xda-developers.com/moto-x/general/guide-unlock-sim-flash-retail-lollipop-t3236783. I kept receiving the "No mobile network available" prompt. I mixed & matched network settings....GSM, 4G only, CMDA/4G, etc. No luck. I flashed back to stock 4.4.4 by manually flashing this file: ghost_sprint-user-4.4.4-KXA21.12-L1.28-28-release-keys-cid9.xml. That would be a clean sbf install? Well, as clean as a downgrade can be.
I am still green to the scene, but I managed to make it through the guides without bricking my phone. The "No mobile..." prompt still exists. The best I can come up with is that the OTA update last month bugged my antennae firmware. Would a clean OS install change all antennae firmware? Sprint tech reps are baffled by the prompt because they say "it seems fine on their end".
Current setup
Device is Moto X 1st Gen (xt1056)
android version is 4.4.4
system version is 212.144.2.ghost_sprint.Sprint.en.US
build nunber is KXA21 . 12-L1 .28.2
kernel version is 3. 4. 42-g6b785f7
Putting on my tin foil hat. This would be the perfect way to soft brick a customer's phone. Is there a thread on xda with other corporate paranoiders I could join :silly: