A NOTE TO CLARIFY MODEMS AND FLASHING THEM: Your Modem is your BASEBAND. Flashing a Modem will UPDATE your BASEBAND.
Flashing a Modem and Updating your BASEBAND does NOT change or lock down your bootloader at all/any further than it already is.
The BOOTLOADER is what determines how locked down your phone is and WHICH root/recovery method can be used.
IF you are on MDB or MDL BOOTLOADERS then flashing these modems will NOT effect your ability to flash anything or change your bootloader.
If you are on MF3 or Newer bootloader then you can use SAFESTRAP to have its recovery and flash compatible Roms AND these modems.
If you are on MK2 bootloader you can use MK2's version of Safestrap and flash compatible Roms and Any of these modems.
To VERIFY "WHICH BOOTLOADER" you have on your phone you can follow these basic instructions.
1. Get "Terminal Emulator" from the play store.
2. Open Terminal Emulator and then type "su" without the quotation marks.
3. Hit the "x" and close Terminal Emulator once you have granted it Root Permission
4. Open Terminal Emulator app, type "su" without the quotes
5. Type getprop ro.bootloader
6. Look at the first line that shows up which is the installed bootloader. It should read "something like"
I337UCUAMDB/ I337UCUAMDL/ I337***MK2/ etc. etc.
I have put the other ATT Modems here as well for users to find the ATT specific modems in one place or in case you need/want to go back to your previous modem. Flashable in CWM/TWRP Recoveries.
Android File Host Links to ALL MODEMS https://www.androidfilehost.com/?w=files&flid=28808
ATT OC3 5.0.1 MODEM
Thanks to Muniz_ri for posting his stock partition file which I grabbed the modem from.
ATT NJ4 4.4.4 Modem
Thanks to Muniz_ri for uploading a stock rooted ROM from the .cfg 4.4.4 firmware update. Pulled modem from his rom.
ATT NI1 KK MODEM
THANKS to Venom0642 for providing the modem and Muniz_ri for the firmware dump.
ATT NC1 OFFICIAL UPDATE KK MODEM
THANKS to Jeboo for providing it
ATT NB1 OFFICIAL KK MODEM 2-26-2014
THANKS to Jeboo for making it for us...
ATT FMLD LEAKED KK MODEM 1-26-2014
THANKS to Shoman for extracting the modem for us!!!
ATT MK2 MODEM11-28-2013 http://devhost.xda-developers.com/2S0
ATT MJ9 MODEM 11-14-2013
Thanks to Design Gears for his leaked MJ6 4.3 ATT Firmware.
ATT LEAKED MJ6 MODEM
ATT MF3 MODEM 7-9-2013
ATT MDL MODEM MARCH 2013
ATT MDB MODEM MARCH? 2013 Came with Release of phone
FOR SAFESTRAP MF3 and NEWER USERS
This is what a tester DeadlySin9 did. He flashed the MJ6 Modem and it worked fine. He then tested going back to the MF3 modem. So if your signal becomes worse you CAN flash back to MF3 Modem but IF you have problems you may need to follow his advice below.You can see his comments here:
Baseband is back on MF3 after flashing. Interestingly enough it's booted into stock and safestrap isn't loading. SuperSU is loaded and giving toast notifications and even let me grant to TiBu. Will try reinstalling SS and/or rerooting and see what works.
Back into my Safestrap slot, modem stuck across reboot. Rerooting was necessary, although root wasn't lost (go figure). Data and service are enabled just fine. Will try going back to MJ6 modem
FOR MK2 SAFESTRAP USERS
THANKS to Churapa for letting us know these DO work for the newer safestrap as well. Here is his comments and how he did it.
I337 ATT 32 GB PIT FILE REPOSITORY (Pulled from my 32GB I337)
DOWNLOAD LINK http://devhost.xda-developers.com/le3
I337 ATT 16GB PIT FILE REPOSITORY
DOWNLOAD LINK http://devhost.xda-developers.com/zxW
Thanks to "mbonus" and "Beast330" for getting us the 16GB pit files.
I am thinking there is no difference between the 16GB and 32GB pit file as they are exactly the same size and have the same exact md5 even though pulled from different phones.