Alex Ruben
How To Restore Lost Fingerprint on OnePlus 9 Pro After Downgrading from Android 13 to 11
So, if you’ve gone from Android 13 down to 11 on your OnePlus 9 Pro and now your fingerprint sensor is acting up or just straight-up dead, you’re probably feeling a bit frustrated. That’s because sometimes, when flashing or downgrading, some sensors or hardware features get weirdly broken—probably due to missing or outdated files. Luckily, there’s a way to fix it without sending it back to the shop. The idea here is to flash the correct persist file (because Android’s fingerprint data is stored in a hidden dedicated partition), which hopefully brings your fingerprint sensor back to life. No promises it’ll work on every setup, but it’s definitely worth a shot to restore that security feature.
Just a heads-up: messing around with fastboot and flash commands can be risky if you’re not careful. Make sure to follow each step precisely, keep your device charged (>50%), and double-check you’ve downloaded the right persist file for your exact device model and OS version. Because, of course, Android has to make it harder than necessary sometimes.
How to Fix Fingerprint Sensor on OnePlus 9 Pro After Downgrade to Android 11
Method 1: Flash the Correct Persist File
This is the main game-changer. The fingerprint data is stored in the persist partition, and when downgrading, that partition might not get properly updated or might get corrupted. Flashing the right persist file can restore that functionality. It typically applies if your fingerprint sensor suddenly stopped working or won’t register new fingerprints after the downgrade.
Get Your Device Ready and Enable Debugging
- Make sure your OnePlus 9 Pro has Android 11 installed and is unlocked (bootloader unlocked.
- Download the latest AOSP Platform Tools for your OS (Windows, macOS, Linux). These include adb and fastboot commands.
- Download the correct persist.img file suited for your device. You can find it on XDA forums, or from repositories like GitHub: Winhance. Remember, get the exact match—wrong files can mess things up more.
- Connect your phone to the PC via USB. Make sure you’re using a good cable—sometimes cheap or faulty cables cause weird disconnects, and that messes with flashing.
- Enable Developer Options: Settings > About Phone > Tap Build Number 7 times. Then go back, find Developer Options, and turn on USB Debugging.
Transfer the Persist File into Your ADB Folder
- After downloading the persist.img, move it to your platform-tools folder (where adb.exe and fastboot.exe live). On Windows, it might be something like
C:\platform-tools. - Copy the persist.img into that folder—easy to find later when running commands.
Access Command Line/Terminal in ADB Folder
- On Windows: Shift + right-click inside the platform-tools folder and pick Open PowerShell window here or Open command window here.
- On Mac/Linux: Open Terminal, then navigate to that directory with
cd(e.g.,cd ~/Downloads/platform-tools)
Reboot Your Phone into Fastboot Mode
- In the command prompt or terminal, type:
adb reboot bootloader - Device should restart into fastboot mode. If it’s not showing fastboot screen, hold volume down + power button manually while powering on.
Flash the Persist File
- Once in fastboot mode, run:
fastboot flash persist persist.img - Note: Some setups might require you to unlock or relock the bootloader again, but usually this isn’t necessary just to flash persist, unless it’s a root or security issue.
- Wait till the command completes—no disconnecting. You should see a “finished” or “OKAY” message.
Reboot the Device
- Type:
fastboot reboot - Device will restart into Android. Sometimes it takes a few minutes for fingerprint sensors to reinitialize fully, so be patient.
Test Your Fingerprint
- Head into Settings > Security & Lock Screen > Fingerprint and try adding a new fingerprint. If it recognizes your finger, victory!
Extra Tips & Troubleshooting
- If the device refuses to boot into fastboot mode, double-check your driver installation. On Windows, make sure you installed the OEM driver for OnePlus (via the OnePlus driver package or from the device manager).
- Sometimes, the persist file isn’t the right version or isn’t compatible—double-check. Or try using a different persist.img from the same firmware version.
- Keep your phone charged, at least over 50%, so the process doesn’t get interrupted halfway. Bricking your device is possible if power dies during flashing.
- If nothing works, consider a full factory reset, but that’s another story—usually more drastic.
Wrap-up
Flashing the correct persist file can do wonders for fixing fingerprint issues after downgrades. Honestly, not sure why it isn’t default included in the downgrade process, but hey, here we are. Be cautious, follow each step, and hopefully that sensor springs back to life. It’s kind of weird, but on some setups, it only takes a reboot or flash to get the fingerprint sensor working again. Good luck, and fingers crossed this helps!
Summary
- Download the right persist.img for your device and OS version.
- Enable Developer Options & USB Debugging.
- Transfer persist.img to your ADB folder.
- Boot into Fastboot (adb reboot bootloader).
- Flash with
fastboot flash persist persist.img. - Reboot, then test fingerprint setup.