Update Galaxy S3 SGH-T999 to Android 4.2.2 SlimBean Build 6 Custom ROM

T-Mobile Galaxy S3 SGH-T999 has been needing the new Android 4.2.2 Jelly Bean for quite a while now. When we found there was custom firmware whose aim was to get that OS on this kind of smartphone, we downloaded it and made this tutorial.

We discovered the following (among many others things) after we used the tool: no more bugs, Auto-Brightness capability, improved T9 dialer and many great features.


Let’s now get the Android 4.2.2 on your phone, shall we? First rule: prepare by flashing USB drivers for the handset on your laptop, charge the phone’s battery, use the Galaxy S3 T999 that is not locked to a carrier and whose bootloader is unlocked, make backups via our instructions (the data on the internal memory needs to be backed up to an external SD card) and, last but not least, turn USB Debugging on.


Second rule for our guide: follow the steps which will smoothly update your smartphone to the desired OS.

  1. Start off with the following indications: download and on your notebook and, when done, plug your handset to your comp.
  2. The two zip files from the first step will have to be copied from where they are and pasted to a new location: the phone’s SD card. At the end of the copy + paste process, you should unplug the Galaxy S3 SGH-T999 from your PC.Galaxy-S3-SGH-T999
  3. After you make sure your device is no longer powered on, you need to enter it in Recovery Mode like this: simultaneously press and hold Volume Up, Power and Home; then wait for the logo of the manufacturer to appear so that you can stop pressing those keys for a bit, then hold them once more and you’ll be in the required mode in a matter of seconds.
  4. After that ends, you will have to proceed with the following instruction: operate a set of three wiping actions. We will start with the first one for which you should opt for the following: Factory Reset/Wipe Data and afterwards choose “Yes” and return to the Recovery Menu. The second task should happen like this: opt for Wipe Cache Partition. The last of the wiping actions: choose Wipe Dalvik Cache.
  5. Wait a couple of seconds again until each of the tasks above has been completed. Now choose a couple of options which are as follows: Install zip from SD card and Choose zip from SD card.
  6. Your next task should go in the following manner: after you find the SlimBean 4.2.2 Build 6 ROM, choose it via the Power key and then have this action confirmed. The flashing of the ROM will commence shortly, so have patience for this portion of our tutorial.
  7. To be able to install the Google apps package, you need to repeat what you performed for this paragraph; however, make sure you opt for the SlimBean Gapps. After both processes end, you need to return to the phone’s Recovery Menu.
  8. [sc name=”banner-jos”]Having landed in that place, here’s the option you need to restart your device. Then wait for the Galaxy S3 SGH-T999 to finally boot into the SlimBean Build 5 custom ROM. The latter will be waiting for you in the device’s “About phone”!

NOTE: In case you wonder how to get the old ROM back on your smartphone, we recommend the following set of actions: boot the T999 into Recovery, opt for Backup&Restore and search for your tool in a list that will come on the display. And that’s a wrap.