Install CM10 Android 4.1.1 Nightly on T-Mobile Galaxy S3 SGH-T999 Jelly Bean Custom Firmware

• Last modified: Android Tips

T-Mobile Galaxy S3 SGH-T999 can now be updated to the latest CM10 Android 4.1.1 nightly Jelly Bean. CyanogenMod 10 will hopefully not take a long time like the CM9, but for those who want to catch the development from the early days, here it is. You can install CM10 Android 4.1.1 Nightly Jelly Bean on T-Mobile Galaxy S3 T999. Remember, this is not an official Jelly Bean firmware by Samsung. This is a third-party custom firmware.

In this tutorial, we will guide you through the process of how to install CyanogenMod 10 (CM10) Android 4.1.1 Nightly Jelly Bean on Galaxy S3 T999 with complete steps. Don’t forget to backup your data from the tips given below or best would be to make Nandroid backup.

Disclaimer: All the tools, mods or ROMs mentioned below belong to their respective owners/developers. We (TeamAndroid.com) or the developers are not to be held responsible if you damage or brick your device. We don’t have you on gun point to try out this tutorial ;-)

CyanogenMod 10 (based on Android 4.1.1) Jelly Bean is still in nightly stage and will take several months before it gets matured enough to be released in a beta version. By installing this, you should remember that you may encounter bugs in the ROM after installation.

Make sure you have installed all your USB drivers for the T-Mobile Samsung Galaxy S III to connect it with the computer. Download Samsung Galaxy S3 USB drivers! Apart from just the USB drivers, there are a few more things that you need to take care of.

1. You need to enable USB debugging mode. This helps to connect your Android phone with the PC. See here: How to Enable USB Debugging.

2. Your phone battery should be 80-85% charged. If your phone goes off suddenly because of battery, during flashing ROMs or installing mods and updates — your phone might go dead permanently. See here: How to Check Battery Percentage.

3. Backup all your important data that you might need as soon as your flash a new ROM, or make a backup for just in case, you never know when anything might go wrong. See below on how to backup data:

Data can also be backed up using Samsung KIES for their devices, but if you backup data manually, you get more options what top choose from and it is very easy to move data across Android devices from different manufacturers, i.e moving Samsung Galaxy Note backup data to HTC One X.

4. Your phone should be factory unlocked. Additional instructions for locked Android devices will be added in the tutorial for unlocking devices.

Now, let’s proceed with the tutorial on the next page and install CM10 Android 4.1.1 Nightly Jelly Bean ROM on Galaxy S3 SGH-T999.


  • Daz

    “4. Your phone should be factory unlocked. ” .. my phone is locked to t-mobile, how can i go about installing CM10?

  • http://twitter.com/peezrow AJ Leight

    To go from 1 nightly to the next do you simply flash the rom without clearing data or anything? For example, I’m running the cm10 nightly from 8/29 at the moment and want to flash the newest one from 9/19. Thanks in advance!

    • http://www.sizzledcore.com Haris Nadeem

      You can go on without clearing the data in that case. But if you vome across FCs or issues, then wipe it.