If you are one of those who often tryout custom ROMs on your OnePlus One, you should take care of EFS data of your device, because EFS data contains all networks related things such as IMEI number, Wireless MAC address, baseband version, etc. Once it is lost, you will not be able to use your phone on any mobile network. Also, you cannot use Wi-Fi, Bluetooth, etc. Therefore, you should always make a backup of the EFS data before installing a custom ROM.
In this tutorial, we show you how to backup OnePlus One EFS data and restore it when IMEI & SIM not detecting issue occurs. Developed by an XDA contributor Paresh Kalinani, the one-click EFS backup & restore tool for OnePlus One make your job a lot easier. It is one-click tool that lets you easily backup the EFS data on your phone and restores it when it is required.
Though this one click method does not require TWRP recovery installed on your OnePlus One (as in other method), you need to setup ADB and Fastboot driver in your computer. Read this simple guide to know how to setup ADB and Fastboot driver on Windows.
How to Backup EFS Data on OnePlus One
1. Enable USB Debugging on your phone from settings menu (Settings -> Developer Options ->USB Debugging). If Developer Options is not found, go to Settings -> About Phone and tap the build number 7 times to enable the option. You will see ‘Developer Options’ above About Phone in settings.
2. Download the One-click tool [HERE], and extract the content. Transfer ‘Backup EFS.bat’ file to ADB folder.
3. Connect your phone to your PC, go to ADB folder and double click the ‘BACKUP EFS.bat’ file.
4. Press any key on the computer and the tool will back up the EFS data. Two files will show up on the same folder: ‘modemst1.bin’ & ‘modemst2.bin’.
How to restore EFS data on OnePlus One
1. Copy the ‘RESTORE EFS.bat’ and paste in the ADB folder.
2. Place previously backed up ‘modemst1.bin’ & ‘modemst2.bin’ in the ADB folder (it should be there if you never moved it after backing up).
2. Double click the ‘RESTORE EFS.bat’. It will restore EFS data and IMEI on your OnePlus One.
Whenever you need to backup and restore EFS data and IMEI number on your OnePlus One, you can use this simple one-click tool. (Source – XDA)
