Who can disagree with the very fact that connectivity is the most striking feature of a smartphone? And when it comes to network signal connectivity EFS data is probably the most sensitive thing. I see many people complaining that their phone is not able to access any network and data services because the IMEI of the device was lost. The problem of EFS/IMEI loss often occurs due to the following reasons:
- Downgrading or upgrading your phone's firmware manually.
- Installing a custom ROM.
- Any kind of bad flashing or clash between the old and the new EFS partition systems.
Nexus 5 EFS Backup:Anyway, if you own a Nexus 5, autoprime from XDA has made a script that backs up the EFS partition of your device to your phone's SD card. The EFS data is backed up as a flashable Zip that can be easily flashed back using a custom recovery. The backup zip is saved to /sdcard/EFS_Backup/. In case you do not find it in that location, check the following directory: /sdcard /data/media/EFS_Backup/. Please note that the EFS backup script is available as a zip file that can be flashed/run via CWM or TWRP recovery. Therefore, your Nexus 5 must have any of these recoveries and rot access on the device. Now here is how you can flash the EFS data of your Nexus 5:
- Download the following file: Nexus_5_Backup_EFS.zip
- Copy it to your device.
- Boot the phone into recovery mode by holding the Volume Up+Down and Power keys together for a few seconds.
- When you are in the Bootloader mode, highlight the Recovery option and press the Power button to select it.
- In the CWM/TWRP recovery mode, select the install option, select Nexus_5_Backup_EFS.zip and confirm the installation.
- Your phone's EFS partition will be backed up in a matter of moments.
- You can then reboot the device.
Nexus 5 EFS Backup via TWRP Recovery:There is yet another and probably an easier method to back up the EFS on your Nexus 5 if you have TWRP installed on your device. TeamWin has now integrated the EFS backup and restore feature in the latest version of TWRP recovery.
- Boot your phone into recovery mode.
- Tap the "Backup" button.
- Then check the EFS option in the list.
- Finally, swipe the confirmation slider.
- Reboot the device.
- To recover the lost EFS , you can select the "Restore" option next time.