FORUMS

[GUIDE] Fix Fingerprint Scanner with "corrupt" persist in 15 minutes!

846 posts
Thanks Meter: 391
 
By starcms, Senior Member on 6th July 2020, 06:42 PM
Post Reply Email Thread
Omg, I've been messing with this thing for 2 months trying to fix it, all because I didn't take a backup of my /persist as soon as I got the phone, but there is a way to fix it!!! The only pre-requisites are that:
A) you still have your own /persist (that came with your specific phone, didn't overwrite it with one from the forums and didn't save your original somewhere) AND
B) all sensors still work (only the fingerprint scanner is broken) AND
C) that you have NEVER ran the hidden fingerprint calibration tools accessible from *#808# (unless you have a backup of /persist from before you did that)

Follow these simple instructions and enjoy:

https://forum.xda-developers.com/one...print-t4126455

You can ignore the entire part about having to run the MSM tool to roll back to a previous version of OOS (Step 2). Therefore, no data is lost, no factory reset is required, etc.

Also in very first part of Step 4, you need to dial *#808#, not *#801#

It took me less than 15 minutes and now it's good as new!!! Please give the OP thanks! He spent almost 200 hours figuring this out (and I don't doubt it; I must have spent easily over 20 hours myself and didn't get anywhere...). All I did was find his genius instructions and post them here.

Edit: And to add one last step to the guide, after you finish and get the fp scanner working again, please be sure to take a backup of your now fixed persist partition and store it in at least two different locations. Because if you are reading this, you are most likely modding your phone with at least Magisk (why else unlock the bootloader? ;) and almost anything can cause persist to be corrupted. For me, it was simply installing a bad build of magisk canary back in May that did it. It's not just important for those installing aftermarket ROMs. It's vital for anyone who even thinks about unlocking the bootloader on this device. Because even the act of relocking the bootloader has caused persist to be corrupted for some...

Edit2: If you run the MSM tool after fixing persist, or manually relock the bootloader, you'll wind up with your FP being broken again. I'm assuming because the checksum of the "fixed" persist doesn't match that of the original, unmodified persist, so it gets marked as corrupt again. So you'll need to unlock the bootloader and restore/flash your backed up, fixed persist (you did back it up this time, right? ;) Impossible to run msm tool to get back to stock AND have FP working. Bootloader must be unlocked after using msm tool and fixed persist restored.
The Following 4 Users Say Thank You to starcms For This Useful Post: [ View ] Gift starcms Ad-Free
11th July 2020, 06:07 PM |#2  
the hellboy's Avatar
Senior Member
Flag Nepal, the country of the Mt. Everest and the birthplace of lord Gautama buddha
Thanks Meter: 40
 
More
please help HD9010 indian firmware currently..before i had global
i messed up my persist too while reverting back from open beta to stable via fastboot
now fingerprint enrollment error
i tried the guide but its not the same with 7tpro

there wasnt 'gf_persist.so' in data folder of my extracted persist.img
and calibrating was confusing for me but i did it upro my limit but i didnt have those many reds as the original OP had in his guide video while calibrating the fp
so please can you be kind enough to share your whole process that you used to manage the fingerprint error issue?
like what roms you used before and after or during fix?

and lastly, since the backedup persist didnt work i deleted and again backedup the persist in next attempt so it means my fingerprint is gone permanently? maybe?

please help me..ive spent my whole night and day searching and trying workarounds flashing roms back and forth
11th July 2020, 06:55 PM |#3  
OP Senior Member
Flag New Orleans
Thanks Meter: 391
 
More
Quote:
Originally Posted by the hellboy

i messed up my persist too while reverting back from open beta to stable via fastboot
now fingerprint enrollment error
i tried the guide but its not the same with 7tpro

there wasnt 'gf_persist.so' in data folder of my extracted persist.img
and calibrating was confusing for me but i did it upro my limit but i didnt have those many reds as the original OP had in his guide video while calibrating the fp
so please can you be kind enough to share your whole process that you used to manage the fingerprint error issue?
like what roms you used before and after or during fix?

and lastly, since the backedup persist didnt work i deleted and again backedup the persist in next attempt so it means my fingerprint is gone permanently? maybe?

please help me..ive spent my whole night and day searching and trying workarounds flashing roms back and forth

I used his exact instructions on my 7T Pro 5G McLaren edition from T-Mobile. With a few helpful tips I added. You must have the global version of the 7T Pro McLaren since you are talking about open beta and stable releases. Unfortunately I can't help you there. It seems that the TMobile 7T Pro 5G McLaren is much more similar to the OP8 in some ways than the global 7T Pro, especially when it comes to OOS, partitioning, extra security crap, etc.

Edit:. You are in the wrong forum. You don't even have the global 7T Pro McLaren. You have the HD1910 Global (originally Chinese version) 7T Pro. Wrong forum. The 7T Pros didn't even have this issue (or if they did, it was no where near as widespread, I've never even seen it mentioned a single time). To the best of my knowledge, it began with the 7T Pro 5G McLaren from T-Mobile which was the newest phone released by 1+ until the OP8.

And if you deleted your backup of your original persist after trying to fix it unsuccessfully, it's now broken forever regardless. You need to RMA.
9th August 2020, 09:38 PM |#4  
Junior Member
Thanks Meter: 1
 
More
Late response, but this worked 100% for me after switching back to stock from AOSiP.

Thank you!
10th August 2020, 04:42 AM |#5  
OP Senior Member
Flag New Orleans
Thanks Meter: 391
 
More
Quote:
Originally Posted by derget1212

Late response, but this worked 100% for me after switching back to stock from AOSiP.

Thank you!

Glad to hear it worked!


One important thing to add:

If you run the MSM tool after fixing persist, or manually relock the bootloader, you'll wind up with your FP being broken again. I'm assuming because the checksum of the "fixed" persist doesn't match that of the original, unmodified persist, so it gets marked as corrupt again. So you'll need to unlock the bootloader and restore/flash your backed up, fixed persist (you did back it up, right? ;). Impossible to run msm tool to get back to stock AND have FP working. Bootloader must be unlocked after using msm tool and fixed persist restored.
12th August 2020, 12:58 PM |#6  
Senior Member
Thanks Meter: 51
 
More
Quote:
Originally Posted by starcms

Glad to hear it worked!


One important thing to add:

If you run the MSM tool after fixing persist, or manually relock the bootloader, you'll wind up with your FP being broken again. I'm assuming because the checksum of the "fixed" persist doesn't match that of the original, unmodified persist, so it gets marked as corrupt again. So you'll need to unlock the bootloader and restore/flash your backed up, fixed persist (you did back it up, right? . Impossible to run msm tool to get back to stock AND have FP working. Bootloader must be unlocked after using msm tool and fixed persist restored.

in the guide it tells you to get your phone into factory mode but does not tell you to take it out of factory mode. of you turn factory mode off and use the msm tool will fingerprint still work afterwords
12th August 2020, 05:19 PM |#7  
OP Senior Member
Flag New Orleans
Thanks Meter: 391
 
More
Quote:
Originally Posted by cgrimm9

in the guide it tells you to get your phone into factory mode but does not tell you to take it out of factory mode. of you turn factory mode off and use the msm tool will fingerprint still work afterwords

Apparently you need to reread the instructions
12th August 2020, 06:16 PM |#8  
Senior Member
Thanks Meter: 51
 
More
I did step three says.
3. Next step is to unlock the built in 'Factory Mode' I have a guide on how to do this below.
https://forum.xda-developers.com/one...-root-t4118527

No where on this instructions says to relock the factory mode. I am just asking if you where to do that will fingerprint scanner work after doing msm tool.

I did the process 2 times now. Have no interest in doing it again unless I need to update. I just putting some thought in why I don't know if it's relavent or not just asking. sometimes a difficult problem can have a easy solution just got to figure it out
12th August 2020, 06:32 PM |#9  
OP Senior Member
Flag New Orleans
Thanks Meter: 391
 
More
Quote:
Originally Posted by cgrimm9

I did step three says.
3. Next step is to unlock the built in 'Factory Mode' I have a guide on how to do this below.
https://forum.xda-developers.com/one...-root-t4118527

No where on this instructions says to relock the factory mode. I am just asking if you where to do that will fingerprint scanner work after doing msm tool.

I did the process 2 times now. Have no interest in doing it again unless I need to update. I just putting some thought in why I don't know if it's relavent or not just asking. sometimes a difficult problem can have a easy solution just got to figure it out

Yes, you can relock factory mode when done. Just re-edit those 2 lines. And once you have your FP working again, please be sure to make a backup of your fixed persist.img. Then you'll never have to do all the steps again. Simply restore your fixed persist.img if FP ever breaks again.
29th August 2020, 11:47 PM |#10  
Inactive Recognized Developer
Flag Snohomish, WA
Thanks Meter: 16,267
 
Donate to Me
More
Quote:
Originally Posted by starcms

Omg, I've been messing with this thing for 2 months trying to fix it, all because I didn't take a backup of my /persist as soon as I got the phone, but there is a way to fix it!!! The only pre-requisites are that:
A) you still have your own /persist (that came with your specific phone, didn't overwrite it with one from the forums and didn't save your original somewhere) AND
B) all sensors still work (only the fingerprint scanner is broken) AND
C) that you have NEVER ran the hidden fingerprint calibration tools accessible from *#808# (unless you have a backup of /persist from before you did that)

Follow these simple instructions and enjoy:

https://forum.xda-developers.com/one...print-t4126455

You can ignore the entire part about having to run the MSM tool to roll back to a previous version of OOS (Step 2). Therefore, no data is lost, no factory reset is required, etc.

Also in very first part of Step 4, you need to dial *#808#, not *#801#

It took me less than 15 minutes and now it's good as new!!! Please give the OP thanks! He spent almost 200 hours figuring this out (and I don't doubt it; I must have spent easily over 20 hours myself and didn't get anywhere...). All I did was find his genius instructions and post them here.

Edit: And to add one last step to the guide, after you finish and get the fp scanner working again, please be sure to take a backup of your now fixed persist partition and store it in at least two different locations. Because if you are reading this, you are most likely modding your phone with at least Magisk (why else unlock the bootloader? and almost anything can cause persist to be corrupted. For me, it was simply installing a bad build of magisk canary back in May that did it. It's not just important for those installing aftermarket ROMs. It's vital for anyone who even thinks about unlocking the bootloader on this device. Because even the act of relocking the bootloader has caused persist to be corrupted for some...

Edit2: If you run the MSM tool after fixing persist, or manually relock the bootloader, you'll wind up with your FP being broken again. I'm assuming because the checksum of the "fixed" persist doesn't match that of the original, unmodified persist, so it gets marked as corrupt again. So you'll need to unlock the bootloader and restore/flash your backed up, fixed persist (you did back it up this time, right? Impossible to run msm tool to get back to stock AND have FP working. Bootloader must be unlocked after using msm tool and fixed persist restored.

yep. same here spent so much time on it. Then me and that dev crossed paths. i told him what i found and he told me what he found and together it birthed that hack

fp also works in custom roms now
The Following User Says Thank You to albinoman887 For This Useful Post: [ View ] Gift albinoman887 Ad-Free
3rd September 2020, 02:17 AM |#11  
Member
Flag Washington
Thanks Meter: 21
 
More
So this fixed my issue with registering my fingerprints, but even after registering 5 prints, when I go to unlock my phone or anything that uses my prints scanning fails like 90% of the time. I have to press really hard or just put in my pin to get my phone to unlock. I removed my screen protector and cleaned my screen. Is there a way to recalibrate the scanner?
Post Reply Subscribe to Thread

Guest Quick Reply (no urls or BBcode)
Message:
Previous Thread Next Thread
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes