If you are planning to replace, return, sell, or repair your Galaxy S III, then you should restore your device to official stock firmware/ROM, so that others don’t know if you’ve made modifications to your device. If your current Galaxy S3 on stock rooted ROM and think that just by doing a factory reset will restore the device to a stock ?, you’re wrong, even a factory reset doesn’t remove root access.
It could be more complicated if your device’s bootloader is unlocked and you perform flash custom ROMs/kernels frequently, as you may know several Samsung phones has the ‘flash counter’ feature that serves to keep track of how many times you are doing flash custom ROMs via Odin.
Here are some steps you can take to restore your Galaxy S3 (I9300, SCH-I535, SPH-L710, SGH-I747, SGH-T999) to stock firmware:
- Do a factory/hard reset, this can be done to restore your device to its original state before you install apps from the Play Store and change settings on the phone, but you may need to backup all apps and data using MyBackup app if you don’t want manually install it later. It can be done by going to Settings > Storage > Factory Data reset and then reset everything, if you have installed a custom recovery (CWM) you can do so by choosing the ‘Wipe data/factory reset’.
- A required tool to able to return to stock is Odin3.
- We also need a stock firmware for Galaxy S3 all variants Verizon, T-Mobile, Sprint, US Cellular, Bell, Rogers, etc.
- Checking Galaxy S3 flash counter, to begin this you need to go into the ‘download mode’ by pressing and holding three buttons, ‘volume down + home + power’ for a few seconds, then Warning!! message will show up and then press volume up button to continue.
- You should entering Download mode/Odin mode and look at the Custom Binary Download, if ‘No’ it’s not necessary to reset flash counter, but if ‘Yes’ you are advised to do so.
- To alter the flash counter to 0/No you need to install TriangleAway app from Chainfire, you can download it free here, but if you want to support the developer you can purchase via Google Play.
- Now it’s time to flash latest official stock firmware, enter into download mode again, and then connect your device into PC thru USB.
- Open ODIN, on File [Download] menu, hit PDA button then find stock firmware file that you’ve downloaded in Step.2. On option, keep Auto reboot and F. Reset Time checked.
- Now it’s time to hit “Start” button to begin flash process.