Ive had my phone for a year, came 4.2 stock, I've flased multiple roms, modem's never had any problems. The other day outgoing messages stopped, on hyperdrive 18.1, so I factoy reset reflashed rom then no sim message. So I went back to my stock backup and no sim messag. I oden back to complete stock all is good, re rooted, recovery all good.
So I was previously running cm 10.2 via CyanogenMod installer (noobish to roms and such) and my galaxy would constantly reboot by itself which was annoying so I flashed back to stock and did the ota update to 4.3 which I now regret. I'm not fond of all the changes made and I wanted to try out cm 10.2 again seeing as there is now a stable release.
I'm trying to flash back to stock (MDK). In using the instructions at [GUIDE][VZW Edition]How to root your Galaxy SIII & More!(ROMs/CWM/Stock) with ODIN and the stock firmware for the S4 from Samsung Updates. Unfortunately, the MDK build is not listed there for the S4, or any device.