yashsingh1/xdaforums huggingface dataset:
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] Raziol:
I'm sure your solutions work as defined.

I want to add my 2 cents to this.

For second trick be careful to not perform test fod before recalibrating as it will lock your device with code 0000 and will crash device when you try to unlock screen. Solution is to unplug finger sensor(but you need to disassemble).(i didn't go with it)

When my display cracked recently and I went to unofficial service, after replacement my fingerprint sensor also didn't work.

However technician told me it doesn't need recalibration, just the correct version display for this model, probably with serial codes(maybe there are for pros, not pros, colors black,red, blue, i don't know). So there's deeper knowledge to this, I think.

Check with your technician or order screen for your version(pro|not pro), maybe color variant(?). Great service expressgsm.eu, fingerprint works but have noticed some ghost touches when outside - will verify that

As of December 2022, I had to wait 2 weeks for shipment probably from china and there are shortages as only mine arrived.
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] BenNomin:
For me there is no "FOG fingerprint calibration" in additional tools.

I have an Xiaomi Mi 10T Lite
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] jcagara08:
If only I still had the phone with me and read this very helpful comment of yours nearly 3 years later, I would have had stuck with that notchless (rare genre of Android phones) 9T pro, hate this Pixel 4A of mine, only switch to this phone since it had Google Pay. Sheesh.

Happy New Year to you buddy and more years to come for your beloved 9T pro!
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] LyNChP1N:
I struggled with these issues after a screen replacement - infact, for many months.

Happy to help someone else facing these issues for which the right solutions are hard to find.

Over time i found solutions in random forums on the internet.(very hard to find working solutions)

Note: try velis auto brightness app if your screen becomes too dark in low lit environments. A way to edit default auto brightness values to be higher in dim environments would have been the perfect solution. Using velis for now.

(The actual fix is to go back to miui 10 based on android 9- everything including display and fingerprint work so much better)
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] jcagara08:
I failed to mention that because of this issue, I have sold my phone nearly 3 years ago now and got a pixel 4a (impulsive and stupid decision from my end just cause of the fingerprint and screen sensitivity complications sheesh) now I am missing my 9T PRO like a hot ex that went away...
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] LyNChP1N:
Go back to miui 10.3.5 via fastboot and then upgrade to whichever rom you want. This will fix the issue.

https://xdaforums.com/t/miui-12-fingerprint-unlock-defective.4122135/post-87893923
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] raisonier:
There is any solution yet? there is any CIT menu in the roms like Superior OS, Pixel Experience or Evolution X?
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] LyNChP1N:
Follow instructions to calibrate FOD in this link

https://xdaforums.com/t/miui-12-fingerprint-unlock-defective.4122135/post-87893923
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] Vulgar Indian:
It's the screen guys , I had the same problem , if your fod is not working after update then simply the service centre has fukked wit u , because I went thru the same problem , then after I went back to them and fought wit them they said one of our service person replaced k20 pro screen wit k20 screen to cut costs , so be very careful and don't accept the screen from service centre if for stopped working after update , and tell them I don't accept this screen and I want my money back & tell them if they don't fix the screen with original k20 pro screen then u will go to police or give money back and just go to different service centre , I had same problem and after I created a huge fight in the mi showroom then they went back inside and replaced with original screen then fod worked properly
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] Cowboy_Henk:
The service center where my Xiaomi Mi 9T Pro was repaired answered and admits it wasn't an original Xiaomi screen but OEM. As good as the original but a bit different....

How do I proceed? Does the service center have to replace it?
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] Ash Luhera:
How did you know it's a k20 screen because tomorrow I'm gonna go to service centre what should I told them
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] Cowboy_Henk:
Can you guys answer this?

Did you already try to clean flash Miui 12? Does this resolve the problem?

Did you try register finger print in 11.06, update to miui 12 and then try fingerprint unlock?

Do you also have the screen flickering problem? My screen sometimes goes black and flickers yellow and black. A restart fixes it but it can come back.
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] Rsitalia1993:
I have same problem here cant register fp the system ui crashes and restarts.
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] Cowboy_Henk:
Well I switched back to 11. 06 eea global. Everything works good except the yellow flickering sometimes.

They pulled off the ota update so must realize there is still bugs
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] Rsitalia1993:
tomorrow i go to the store on al custom roms same problem only there is no fod icon while i want to register it so weird.
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] struppiadf:
Hi everybody. Is there an way to figure out which display was installed during replacement?
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] Cowboy_Henk:
Ok OTA to miu 12 eea global is back on system update. Did someone try the update again because maybe they removed the bugs?
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] alpeppas:
Same problem with fingerprint. After update fingerprint didn't worked and when i used the pin the phone restarted to logo miui. I factory reset and i lost everything. then when the instalation wizard ask me if i wanted to configure fingerprint it restarted again. Next time i didnt configure fingerprint and eventually i booted. Yes i have replaced my sceen but the fingerprint sensor is behind the screen is original. The fingerprint sensor in not bount on the screen but in the frame.
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] Cowboy_Henk:
Maybe try clean install of miui 12?
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] KlaverBoer:
I have replaced the display of my wife her Mi 9T Pro myself. On MIUI 11 FOD worked fine. After the update to MIUI 12 it doesn't work, it restarts the phone. And after the installation of Evolution x rom it is impossible to scan because the scanner does not apear anymore. Also DT2W doesn't work.
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] alpeppas:
I did it. No diference. Also a game the walking dead no mans land dont run. After first game logo ,there is a black screen and no sound.
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] Cowboy_Henk:
Did you do the install with recovery rom? I don't find the fastboot rom of eea global.

Strangily the OTA is offline again from internal system update.
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] alpeppas:
I did it from uodater.i downloaded last rom about 2.5 giga and then i press the miui 12 logo 5 times.the option select package enabled and i selected the package i have downloaded. Maybe i must do a clean install from fast fast boot and pc?
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] Rsitalia1993:
Tried yesterday the global same problem but you can try it, i switched back to custom rom with mi9fod extension fod works only with full brightness.
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] meezy5:
When you replace the screen on phone with indisplay fingerprint scanner you have to replace original scanner to new lcd , coz some screens come with their own new scanner and in order to male it work the only way is clean install that calibrates the phone with new lcd and scanner
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] Rsitalia1993:
Damn that is to late its replaced months ago.
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] ordenalfabetix:
The same happened with my MI 9T pro, which had the screen replaced, but fingerprint on display (FOD) worked normally on MIUI 11 (after calibrating by CIT menu).

Now on MIUI 12 it restarts every time the FOD is to be read, which makes it useless, and even forced me to do a factory reset after the update, as it was impossible to get past the home screen.

Entering the CIT menu, I noticed that the FOD hardware is working normally (to enter CIT menu: Settings -> About phone -> All specs -> click many times over "Kernel version"). Once in CIT menu you can test FOD (option 34, "Fod finger print input test") or calibrate it, via tree dot menu -> Aditional tools -> 13 fod fingerprint calibration (which is something that everyone who changed the screen should do, the FOD performance becomes perfect).

I suspect there is some software incompatibility on MIUI 12 with FOD of OEM screens, some software component (driver?) that was present on MIUI 11 is missing.

In any case, only Xiaomi can resolve this quickly, unless it is on purpose (did anyone think of Apple?), which I think is not the case. I trust Xiaomi, it will not leave its customers. In my country it is impossible to obtain the original screen, MI 9T Pro was not even officially marketed here, however it was a sales success via import.
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] Cowboy_Henk:
Indeed I hope Xiaomi recognizes this problem. Everyone with the same issue should report this officially to Xiaomi (it also sends a log) So go to settings and scroll to Services and feedback. Write down the problem and send it.

The OTA is not available via the updater in phone anymore since more than a week now so maybe Xiaomi will re-release the update with the correct drivers.
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] laanrobe:
Ok, sent my feedback to Xiaomi on this issue. Hope they will provide a MIUI 12 update to fix our in-display fingerprint problem. I really miss this functionality...
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] kefeguy:
My Xiaomi 9t Pro has also had its screen replaced and the fingerprint and display were working completely fine until I updated to MIUI 12 today. It's on a restart loop when I try to unlock the screen. Will reverting back to MIUI 11 fix the problem? and if it will how can I do so? Thanks!
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] Dadovvv:
u can try reverting but u need clean install, but before u need to unlock bootloader to be able to flash miui 11 using mi flash tool
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] kefeguy:
How can I do this without unlocking my phone? as my phone just restarts every time I unlock it. Is there a video or detailed guide on how to do this? Thanks so much!
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] ordenalfabetix:
You are in exactly the same situation that I was in after upgrading to miui 12. The only way out of this loop is a factory reset but you will lose all data on the device. To do this, turn on the device with the volume up button pressed and choose wipe data. The device will remain on the miui 12, but you will have the option of not activating the fingerprint sensor.

After this, without fod and with other bugs present in miui 12 related with unlocking, the device is barely usable. I'm using an old phone while I can't find a solution.

I want to downgrade to the miui 11, which worked perfectly, but I don't know how to do it safely, and I also have no experience with bootloaders, flash programs etc.
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] kefeguy:
I don't have any experience with all of that either :( hopefully someone has a comprehensive and easy to follow guide or video so that we can do this? I might also take it into a service center and see if they are able to do this for me.
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] KlaverBoer:
It is very simple to revert to a previous version. But you will lose all your data. You only need adb, fastboot on your phone and the fastboot image from Xiaomi. I will try to find the YouTube video.
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] gigix_xx:
Same problem

i did the OTA update, in miui 11 FP sensor worked just fine, in miui 12 the phone reboots when i try to setup FP. The phone was new, sealed, screen never replaced.
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] KlaverBoer:
Here you can download the fastboot image for your device: https://xiaomifirmwareupdater.com/miui

In this video you can see what to do with the image:

Fast forward to 3:29 if you already have the adb and fastboot files. I see there is also a batch file to keep the storage. I never used that one. I only have used the flash_all.bat. Before you start to flash the image you must boot your phone into fastbood mode (volume down and power button). And i recommend to backup your data. Then flash and wait.

Https://youtu.be/fHmQuQTJoDo

I have performed this action a couple of times and it works great.
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] Cowboy_Henk:
There is now a fastboot rom for MIUI 12, did someone try a clean flash with it?

You can download https://mirom.ezbox.idv.tw/en/phone/raphael/

And how about Xiaomi.eu rom miui 12 or 12.1? Dis some try that?
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] marioowily:
Hi, Im using a custom rom (evo x) and i cant enter CIT mode by clicking on kernel version. Do u know any other way of doing it? Thx
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] KlaverBoer:
Thats not possible in a custom rom. When i fixed my phone with Evo installed on it i had to go back to MIUI to recalibrate the camera with CIT.
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] ordenalfabetix:
No, unfortunately I only know that way.
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] LucasMonOficial:
has anyone tested the EU version? ROM for this problem in firgerprint
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] kefeguy:
Thanks so much! is there a way to backup my data before i reset it?
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] Pdelmo19:
I also encountered same on Miui12 Phone screen replaced Original Part.

Here are the Roms I tried and the result:

EVOX ROM- FIngerprint Working

MIUI11 GLobal and CHina - FIngerprint Working

Miui12 EU - Not Working ( Remove Fingerprint before upgrading to Miui12 or your Phone will always Restart)

Miui12 China - Not Working ( Remove Fingerprint before upgrading to Miui12 or your Phone will always Restart)

Miui12 Global - Not Working ( Remove Fingerprint before upgrading to Miui12 or your Phone will always Restart)
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] Cowboy_Henk:
Thanks very informative.

Did you always try clean installing them?

And please try Xiaomi.eu rom?
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] Sidewinder85:
Anyway to retrieve my files before i factory reset? im stuck at the fingerprint loop.
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] kefeguy:
I need a way too! U can't unlock your device to transfer files either?
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] Sidewinder85:
Yeah, as soon as i unlock it crashes. This is extremely frustrating. I cant even turn on usb debugging.
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] TealeonToast:
Having a similar problem. After updating to MIUI 12 through the settings, the fingerprint reader no longer works and the phone restarts/crashes after putting in the password pattern. Never had the screen replaced.
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] Ybaronp:
Same problem, Replaced screen, did a hard reset and still does not work, A bad company if doesn't accept screen replacements. Against sustainability. So sad and disappointed.
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] KlaverBoer:
With backup data i mean backup your photos and files on your internal storage. If you can't boot into your phone you can try to copy the files once booted into the recovery. I think it is also possible to copy your files using adb but you have to ask or search here on this forum how to do it that way.

Maybe you do not have to backup your files if you choose the right batch file. But i have not tried that option myself. So dont blame me if that doesn't work :D
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] Yogariku:
Are you sure you never replaced your screen but still the phone restart when setup fingerprint? Maybe you buy your phone second and you don't know the screen replaced or not?
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] TealeonToast:
Phone was purchased brand new so should be the original screen
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] igga8003:
Have the same issue.. Right after updating to 12 via wifi phone starts restarting continuously. I've fixed that via resetting it to factory defaults. But I choose restoring my data from cloud. I guess that is the reason why now I can not activate fingerprint (phone restarts once I tried to activate this option). Did someone try to reset to factory defaults without recovery from backup during initial phone setup?
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] braddyjr:
There is no solution at the moment. I have tried every possible option. At the moment I was forced to downgrade miui 11.
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] TealeonToast:
I had to do a factory reset without a backup. Phone is mostly fine now but like you I can't activate the fingerprint reader
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] kefeguy:
Any updates on solutions?
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] ordenalfabetix:
No solution so far, except reverting to MIUI 11, which is not a solution either.
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] Cowboy_Henk:
My phone is very stable on MIU11 (QFKEUXM 11.0.6.0)

I don't see a reason to upgrade. I hear a lot of complains about miui 12, bugs, annoying interface, can't be debloated,...
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] tuSavvy:
What is the difference of MIUI 11 and MIUI 12 in regards to the fingerprint sensor?

I bought my phone second hand and I think the screen was replaced.

Any chance to find out for sure without "opening" the phone. Any information in the system?

Is there something like a device manger?
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] dagda87:
There are alot of videos on YouTube showig the differences between MIUI11/12. Don't be a lazy cow and go there.

To check the screen you can download a multipoint tester for your screen. OEM screen has just 5 points.
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] Cowboy_Henk:
You sure? Mine is also replaced, repair shop said it was an OEM screen. But I did the multipoint test: 10 points!
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] dagda87:
WoW!! Well maybe your phone should work un MIUI12.
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] Cowboy_Henk:
No, fingerprint didn't work. Waiting for a solution or a better update
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] Mymy02:
I'm also facing the same after miui12. How is ur device now resolved?
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] :
Had the same problem, bought a cheap (50€) oled screen, updated to miui 12 and FP gone. I think is something with new firmwares. Downgraded with miflash to miui 11, now it works flawlessly. Thats a shame BTW, hope that gets fixed as soon as possible, battery life on 12.0.3 was fantastic.
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] meezy5:
you can move old fingerprint sensor from broken lcd to new one and it will work no matter what miui u use, i assume u have acces to old screen since u repaired it urself
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] :
Fingerprint sensor is always the same, it's under the screen, not part of it. Doesn't even need to remove it to replace the screen
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] meezy5:
then its strange that it doesnt work i didnt repaired k20 pro specifically yet but few service screen packs for samsungs and huawei for example comes wit screens that has new sensor in it and in order to make it work it required either factory wipe or replace old one.
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] :
It's software and hardware related, maybe the new firmware in miui 12 changed something that in 3rd party screens doesn't get recognized or triggers an error, because in miui 11 everything works fine. Maybe a wiring or a different IC on the screen that miui 11 doesn't care about, but in miui 12 triggers something.
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] awerqw22:
Anyway to flash miui 11 back (im currently on miui 12) on locked bootloader? I still have 100+ hours before bootloader unlock and this is really an annoying issue. i also had my screen replaced with oem screen and it has only 5 multi touch points. I already did try edl mode flash by shorting the 2 points but authorized account is needed to flash
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] Aevum:
awesome, broke my screen today, they swore they used an original piece. now i also have 5 point multitouch for some reason...
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] Dadovvv:
definitely software problem i didn't replace lcd, my fingerprint unlock sensor works good on miui 12 but i can confirm that fingerprint is broken on miui 12 i mean it's bad optimized bcs compared to miui 10 and miui 11 it's a terrible slow and inaccurate on miui 12. Hope it will be fixed, Miui 12 is great visual rom but full of bugs and bad stability, i downgraded to miui 10 and cant believe how phone is fast, stable, and battery friendly.

i was closed beta tester for Miui12 and from beta to stable they released same rom without almost any fix from what we reported as beta testers community.
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] gp.triple:
Same problem here,

Recived today my phone with new screen(sent to service for ghost touch issue) and when i try to set finger print phone reboot.

Did a soft reset without result.

Before the screen replacement everything was working well under miui 12
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] meezy5:
you can apply for complaint at service to fix the issue its their problem in this situation and they have to fix it, but i doubt thes will coz they dont even know about this issue and will think its lcd defect so they will most likely try to replace it with another screen and also i dont believe there are any oem screens for k20 pro, all or them are 3rd party i think, or most of them and oems are very rare, even though they can be described as oem, they are not. I myself saw 2 k20 pros at local resell used phones store and both had weird colors and lower brightness so i immediately knew they are replaced screens.
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] Aevum:
I returned the phone to the service center, i told him fingerprint reader dosnt work after repair and screen went to 5 point multitouch from the regular 10 point, the guy chargered me 160 euros claiming it was an original screen from xiaomi, but the fingerprint reader issue and the multitouch thing makes me doubt it.

hes currently examening what went wrong and says he has a device that copies the screen firmware and codes from one to another.
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] meezy5:
interesting, never heard repair shops do have calibration device for xiaomi screen,myself i have only for iphones. maybe he can fix it then
[Redmi K20 Pro / Xiaomi Mi 9T Pro Questions & Answe] Aevum:
Update, got my phone back, Miui 12, fingerprint unlock works.