This thread exists to give everyone that is just now getting around to taking advantage of their devices the opportunity to do it right the first time while also keeping all the necessary material in one common place. As always: Know what you're doing. Know what device model you have. Know you and your devices limits.
If followed correctly, this 5-step guide can be a very useful tool. These steps are listed in the order in which they should be completed. The intent is to seamlessly backup, root and flash, leaving as little room for error as possible. This process will erase and/or reset everything on your device. All steps are assuming you have backed up your contacts, texts, pictures, videos, etc. I do not take credit for any of this material or information. This is all the work of good people that I have simply brought together. Cheers!
STEP 1: Backing up your IMEI/EFS/NV
Part 1. Having a corrupt IMEI can be a real pain. It seems to happen randomly and having the radio go down on a cell phone really defeats the purpose of owning one. Thankfully it is not a problem that is overly common. Unfortunately, it does still happen. Since it is simplest to be on stock for this attached method, I have listed it as step number 1.
At the end of the "Instructions" section there is a video demonstration. Check it out first.
Part 2. Having a copy of your functioning EFS folder is also something every user should have. A great way to do this is to download an app like Root Browser or Root Explorer and copy the efs folder from your device to either your external micro SD card, your computer or both. This will allow you a much smoother transition back into a fully data-capable and functioning phone in the event your IMEI/EFS is ever corrupted.
STEP 2: Rooting your device
For those of you who want to get most out of your Galaxy S3, you will certainly want to root it. Rooting your I747 gives you lots of benefits like full control over your phone, ability to install custom ROMs, and much, much more...that's why you're here right now reading this. You want it all.
The attached link may be intimidating to you initially, so read over the page a few times to become familiar. Near the top of the page, the second paragraph links you to a video of the rooting process. Watch this to understand better what to do and what you should expect to see during these root procedures. After downloading Odin (the link is just below the video link), just follow the first 2 steps (1. Download the file to flash and 2. Unzip the file contents and flash the rooted firmware) and then return here to continue on to step 3.
stock/rooted-only but cleaner, with less bloatware and without unused apps absorbing resources.
A custom recovery is required and TWRP is recommended
STEP 3: Installing a custom recovery
A recovery image is the system level software for your Android that lets you perform several maintenance and recovery tasks. The stock recovery image is quite limited in what it allows you to do and therefore, flashing a custom recovery image is required to gain full control of your device’s administration. A custom recovery image allows you to perform the following tasks:
- Wipe your phone’s data (Factory reset) and cache
- Make, restore and manage backups of your phone’s operating system and software
- Mount, unmount and format your phone’s internal as well as external storage partitions
- Install a custom ROM or application from a zip file to your phone
- Wipe Dalvik cache and battery statistics
- Make logs for error reporting and debugging
The 2 most common custom recoveries are listed here. Everyone has a preference but they both work well. Take your pick and download from the Play Store.
**ClockworkMod (CWM)** --- OR DOWNLOAD THE APK DIRECTLY HERE (Recommended)
1. Open Rom Manager and tap on Flash ClockworkMod Recovery option in the app.
2. You’ll be asked to select your device, select your device name.
3. As soon as you select the model, it should begin installing the recovery.
4. When it has done installing the recovery, you will get a message for the same on your screen.
*NOTE: I do not recommend Rom Manager as a tool to do anything but just install and update ClockworkMod Recovery Do not flash ROMs from Rom Manager.
**Team Win Recovery Project (TWRP)** --- OR DOWNLOAD THE APK DIRECTLY HERE (Recommended)
1. Once the download is complete launch Goo Manager.
2. On the top right of the screen there is the “options” menu.
3. Tap on options.
4. Then, click or choose the “Install OpenRecovery Script” option.
5. Select “yes” on the prompts that will follow. Now, the app will download and install TWRP Recovery on your S3
*NOTE: I do not recommend GooManager as a tool to do anything but just install and update TWRP Recovery Do not flash ROMs from Goo Manager.
STEP 4: Making a Backup (Nandroid)
Making a nandroid will allow you to try out new ROMs while still keeping a safe backup in the event you experience issues during or after the OS installation. Be sure your device is fully charged before proceeding onto the backup and flashing procedures.
1. Power off your device.
2. Press and hold Volume Up + Home + Power buttons at the same time.
3. Release the power button when the device vibrates and you see the blue script in the top left corner
4. You are now in custom recovery.
5. In CWM go to Backup and Restore and select Backup. In TWRP select Backup. Name and select the options you want. Swipe to backup.
6. After backup is finished, select reboot system now or stay in recovery to continue with this guide.
*NOTE: Be sure to save a copy of this backup to your computer and/or micro sd card. Having a recent backup saved to your computer and micro SD card can be useful if something happens to your phones internal memory.
STEP 5A: Wiping your device
When flashing any ROM, it is always important to follow the proper wipe procedures in order for everything to function properly. There are various levels of wiping based on what sort of transition you may be making. In this guide, I will list the procedures for a full wipe, presuming that you are coming from the stock firmware and changing your OS completely. This is all assuming you have made the appropriate backups. ALWAYS perform the appropriate wipe before flashing a new ROM or update!
1. If you are not already in recovery, boot in now (Vol Up + Home + Power. Release the power button at vibrate and when you see the blue script in the top left corner).
2. Select Wipe data/factory reset
3. Select Wipe Cache
4. Select Advanced and Wipe Dalvik Cache
5. Select Mounts and Storage and format /system
6. If you are transitioning from 4.1 to 4.2 or 4.2 to 4.1, you must also format /data. You will lose all personal data so back it up first.
2. Select Wipe
3. Select Factory Reset and wipe
4. Select System and wipe
5. If you are transitioning from 4.1 to 4.2 or 4.2 to 4.1, you must also select Data and wipe. You will lose all personal data so back it up first.
STEP 5B: Flashing a custom ROM
First, read up on a couple ROMs you're interested in. Make sure they are for your model. Understand that the newest ROMs often still have some small bugs still to be worked out. Once you have decided on a ROM:
1. Download the ROM - If you are downloading a stock/TouchWiz-based ROM, Google Apps (gapps) will be included. If you are downloading an AOSP-based ROM, be sure to download the appropriate gapps as well.
2. From your PC, place the ROM/gapps on your internal or external SD card. Remember where they are.
3. Boot into custom recovery (Vol Up + Home + Power. Release the power button at vibrate and when you see the blue script in the top left corner).
4. Perform the wipe listed above if you have not already.
5. From the main recovery screen:
>>CWM - Choose the "install .zip from SD Card" or "install .zip from external SD card" option (depending on where you placed the files) then navigate to the ROM file, select it and confirm.
>>TWRP - Choose Install and locate the desired ROM on your internal or external SD.
6. If you need to flash gapps, repeat step 5 and select the gapps package.
7. Reboot system. It will take several minutes to load so be patient and don't worry. Once the phone is booted, let it sit for 5 minutes, reboot and enjoy!