[GUIDE] Fix PERSIST.IMG Loss Of Finger Print Sensor

[SchWeinSAuG]

I think maybe try to extract data and engineermode files from the backup persist.img and try again

is this gonna work?
i also got a persist.img backup from when everything used toi work, latest updated ****ed up FP.
Curious how to restore the working files

EDIT: Doesnt work, just gave it a try

 

[Extreme_Ninja2099]

is this gonna work?
i also got a persist.img backup from when everything used toi work, latest updated ****ed up FP.
Curious how to restore the working files

EDIT: Doesnt work, just gave it a try

Have u tried re-calibrating the fingerprint, then transfer the old files from your persist.img and keep just the gf_persist.so file (Don't replace it with the same file name from your persist.img)? This worked for me

 

[SchWeinSAuG]

Have u tried re-calibrating the fingerprint, then transfer the old files from your persist.img and keep just the gf_persist.so file (Don't replace it with the same file name from your persist.img)? This worked for me

well no, just extracted data and engeniermode folder and replaced it in persist folder on phone.
withg old files you mean the files extracted from the working persist.img ?

 

[Extreme_Ninja2099]

well no, just extracted data and engeniermode folder and replaced it in persist folder on phone.
withg old files you mean the files extracted from the working persist.img ?

Didn't u read the instructions? that's is what ur supposed to do... Try replacing the files except for gf_persist.so from ur "working" persist.img. But u have to recalibrate ur fod before doing this like stated in the instructions

 

[SchWeinSAuG]

Didn't u read the instructions? that's is what ur supposed to do... Try replacing the files except for gf_persist.so from ur "working" persist.img. But u have to recalibrate ur fod before doing this like stated in the instructions

thanks!
sure i did, but since instructions are for case if you aint have a working backup persist.img., i was not sure which image you was talking about.
thought it might be easier if i have a persist.img from working status.
gonna give it a try tomorrow.
thanks again

 

[SchWeinSAuG]

Didn't u read the instructions? that's is what ur supposed to do... Try replacing the files except for gf_persist.so from ur "working" persist.img. But u have to recalibrate ur fod before doing this like stated in the instructions

i cant find the FP test which is stated. or did i get something wrong?
hope its Optical calibration?

when i hit Optical calibration i get this popup....

 

[SchWeinSAuG]

i cant find the FP test which is stated. or did i get something wrong?
hope its Optical calibration?

when i hit Optical calibration i get this popup....

just realized i can type in numbers in the popup
anyone an idea what i could do here?

 

[Extreme_Ninja2099]

i cant find the FP test which is stated. or did i get something wrong?
hope its Optical calibration?

when i hit Optical calibration i get this popup....

• Enter Factory Mode as shown in the previous guide. (*#808# in the stock dialer)
• Swipe over to "Device Debugging"
• Select "Finger print test"
• Select "Finger print calibration test (Pure White - 90% Blue)
• Select "Start Test"
• Keep on going through the tests (You must hold an object or your finger over sensor on all BUT THE BLACK RUBBER TEST of these test for it to work!)
• The test will fail and this is what we want. There should be a lot of red lines, if you only have one or two try again.

 

[SchWeinSAuG]

• Enter Factory Mode as shown in the previous guide. (*#808# in the stock dialer)
• Swipe over to "Device Debugging"
• Select "Finger print test"
• Select "Finger print calibration test (Pure White - 90% Blue)
• Select "Start Test"
• Keep on going through the tests (You must hold an object or your finger over sensor on all BUT THE BLACK RUBBER TEST of these test for it to work!)
• The test will fail and this is what we want. There should be a lot of red lines, if you only have one or two try again.

thanks, but only calibration option i have, is this Fingeg print optical calibration, which gives me this popup when i hit it.
Auto test says "Pass"

 

[SchWeinSAuG]

SOLVED!!
I removed all screenlocks, cleared cache, moved data and engeneermode folder, reinstalled update....
dont know what did the trick, but FP is working again.
cheers

EDIT:
Now i know what caused fingerprint no to work.
it was "Universal Savetynet fix" Magisk module.
but there is also a solution module for this issue.

 

[ziedje]

SOLVED!!
I removed all screenlocks, cleared cache, moved data and engeneermode folder, reinstalled update....
dont know what did the trick, but FP is working again.
cheers

EDIT:
Now i know what caused fingerprint no to work.
it was "Universal Savetynet fix" Magisk module.
but there is also a solution module for this issue.

Thank you bro, I was afraid I had to reset my device, but the module fixed it.

 

[faysal0]

Will this rule and the msm tool be the same for op7t?

 

[faysal0]

New video guide below

VIDEO GUIDE


1. *VERY IMPORTANT* We need to back up your broken persist.img and store it in a safe place. PC preferred. We will need this later. Do not leave the backup on the device as the next step will wipe the device.

*IF YOU LOOSE THIS PERSIST.IMG BEFORE WE MODIFY IT WITH A CALIBRATION, YOU LOOSE ALL CHANCE OF FIXING THIS YOURSELF*

*IT HOLDS IMPORTANT FP CALIBRATION DATA THAT WE WILL BE OVERWRITTEN IN THE NEXT FEW STEPS*

Note: This requires root​

Type this into terminal or ADB shell with root privileges.

dd if=/dev/block/bootdevice/by-name/persist of=/sdcard/persist.img

Backup the partition to another device. Preferably a PC as you may need one in the later steps.

2. Next we have to restore our OS to an earlier OOS. (10.5.4 is what I used and recomended)

Use the MSMTool to restore your device to 10.5.4.​

Note: You will loose your unlocked bootloader and will be required to unlock your bootloader once more.​

Guide and Source for MSMTool
MSMTool 10.5.4 Download

3. Next step is to unlock the built in 'Factory Mode' I have a guide on how to do this below.

[GUIDE] Unlock Factory Mode *root*

4. Now we need to perform a FP calibration. We want to fail.

• Enter Factory Mode as shown in the previous guide. (*#808# in the stock dialer)
• Swipe over to "Device Debugging"
• Select "Finger print test"
• Select "Finger print calibration test(Pure White - 90% Blue)
• Select "Start Test"
• Keep on going through the tests (You must hold an object or your finger over sensor on all BUT THE BLACK RUBBER TEST of these test for it to work!)
• The test will fail and this is what we want. There should be a lot of red lines, if you only have one or two try again.

5. We need to extract the the old broken persist.img
NOTE: It is important that we extract the backed up persist.img as it has been unmodified by our recent calibration. This persist.img although broken still has all our working calibrations on it including Finger Print calibrations.

The way I did this is by opening it extracting it via 7-ZIP on my PC​

Once extracted move the 'DATA' folder and the 'ENGINEERMODE' folder to the root of your sdcard.​

6. Download a root explorer. I highly recommend 'Solid Explorer' from the Play Store.

• Open 'DATA' folder and delete 'gf_persist.so'
• Select the 'DATA' and 'ENGINEERMODE' folders you just put on the device and place them at /mnt/vendor/persist/
• It should ask you if you want to keep the old or new files. Select to keep the new.
• Reboot.

7. If you followed all my steps correctly this you should be able to go into settings and add your fingerprints.


Why does this work?

Good question... I think what is happening is something in the persist partition breaks which causes the device to think that the sensor is not calibrated when in fact it still is.
When we start and fail a new calibration this fixes whatever was broken in our partition. But now we have a failed calibration.
So what we do is take the files from our backed up persist partition and move over all the necessary files that have our original calibration. But now our partition has the part of it that wasn't working fixed.

I spent a good many days working on this fix (1-2 hundred hours or so). I hope you can be respectful if you have issues. Please kindly ask below and I'll do my best to help.

Does this formula and msm tool apply to op7t?

 

[PeachMode]

Hello!
I had my screen replaced and now my fingerprint sensor doesn't work properly. It still detects fingers and lets me register new fingerprints but it seems to be offset a bit. Does this tutorial apply to my problem? I tried doing the calibration test in engineering mode and follow the steps but I don't have the proper tools for the rubers so it failed some bits of the calibration.

 

[parcou]

SOLVED!!
I removed all screenlocks, cleared cache, moved data and engeneermode folder, reinstalled update....
dont know what did the trick, but FP is working again.
cheers

EDIT:
Now i know what caused fingerprint no to work.
it was "Universal Savetynet fix" Magisk module.
but there is also a solution module for this issue.

Thank you....I was about the downgrade, wipe, and redo my entire device and this simple fix worked.

 

[dgunn]

I just completed all of these steps and it was unsuccessful for me as well. I did it three times and still receiving the same error

 

[Avneeshan]

hi i am facing a issue after flashing custom rom fails. That the fingerprint is working and it glowing light in screen but it not taking the reading(no improvement in enroll progress). I tried with deleting and flashing the persist file but no improvement. Can you help me with it. https://t.me/T4Tamilan this is my telegram account please help me with this.

 

[Avneeshan]

hi i am facing a issue after flashing custom rom fails. That the fingerprint is working and it glowing light in screen but it not taking the reading(no improvement in enroll progress). I tried with deleting and flashing the persist file but no improvement. Can you help me with it. https://t.me/T4Tamilan this is my telegram account please help me with this.

i am having realme 7 pro rmx2170

 

[dlads]

Sort of done the same thing on my 10 pro.

Hoping this could fix my phone too, really miss my 8 pro with I'd never got this turd.

Do you think this method would work?

Proximity,, brightness sensor, compass all missing.

Fingerprint still working

 

[skyraven83]

Does anyone have a valid Oneplus 8 Pro European version persist.img that I can flash?
Or any other method that does not involve flashing everything and losing everything?

Currently my fingerprint works only if I go in the Engineering Menu and then at the end I specify the test has failed (there's a button that asks me on the newer version).
I use *#899# to access it and 6776 then to do the calibration.
This workaround lasts until the next reboot..so there has to be some local file that if I delete/replace then the setting remains after reboot.

Anyone, any clue?

p.s. already used msm tool and lost most of my stuff once as while trying to remediate the fingerprint I followed a thread that told me to delete locksettings.db. After that one the sdcard did not mount anymore... and later I managed to brick my device => EDL + MSM.