[OnePlus 8 Pro  Guides, News, & Discussion] vrabaci:
AS LONG AS PHONE CAN BE TURNED ON - WHETHER IT IS RECOVERY, FASTBOOT, QUALCOMM CRASHDUMP OR SOMETHING SIMILAR YOUR DEVICE CAN BE FIXED...

WARNING:

Regarding QC MSM Flash tool - make sure you back up persist.img before flashing device otherwise you won't be able to recover fingerprint sensor...

Regarding QC SP IMEI Write tool - You can only use IMEI that is on the box...

Your data will be lost, obviously...

This guide is for EU devices (download links have EU firmware), but it is applicable for other as well as long as you have required firmware...

Required stuff:

Download from GDrive

Passwords:

IMEI TOOL: ustest

MSM TOOL: te123

1.) Make sure to back up EFS, if you don't you will lose ability to make or receive calls.

If you didn't backup EFS that's not problem, I found temp. solution... After doing MSM SMT clean installation your imei wil be 0 but you will be able to make calls. At this point you MUST BACK UP: mdm1m9kefs1, mdm1m9kefs2, mdm1m9kefs3 and mdm1m9kefsc...

After updating your IMEI and OS to latest version you will lose ability to make or receive calls but, you can than do:

fastboot flash mdm1m9kef

fastboot flash mdm1m9kef

fastboot flash mdm1m9kef

fastboot flash mdm1m9kefsc

fasboot flashing lock_critical

...and boom your device is now fixed!!!

1. A) Backing up persist.img DIFFICULTY: 3/5

Download and extract: MSM TOOL 10.5.4, open "MsmDownloadTool V4.0.exe" -> Other -> Next

We're just gonna flash your OS so do not use SMT mode yet (If you don't know what is SMT mode then just follow steps)

Click on TARGET and select EU, click start and wait for it to say "Waiting for device", now when your device is powered off, hold volume up and volume down button and connect it to the cable, MSM should now start flashing your OS

After it's completed (around 5 minutes) you will be able to boot into OS, go to developer options (after setting up device), go to developer options and enable "OEM Unlocking"... Now update your system using local files: UPDATE 10.5.5 on GDrive (extract it, you are gonna find OnePlus zip FullOTA and magisk boot.img) and reboot to fastboot after update, connect your phone to adb and do "fastboot flash boot <magisk.img - from gdrive>" now set up magisk.apk and make sure root is working, go back to adb on your computer and run these commands:

adb shell

su (there will be pop-up and you need to grant root access to shell)

adb shell dd if=/dev/block/bootdevice/by-name/persist of=/tmp/persist.img

Now store that persist.img to your pc

1.B) If your device looks like this and you didn't back up persist.img you will have to play around because I don't know if you can get your fingerprint sensor back without it but if you do please let us know in the comments, you will need to flash using SMT mode...

View attachment 5765273

To flash it via SMT, you need to open MSM V4.0 and click Verify, after you get MD5 Check... you need to click on SMT download mode View attachment 5765291 and now press SMT on top View attachment 5765295 then COM Setup and enable your ports. After you click start it will ask you for password: te123, and also you need to put your original storage size, now press volume up and down on your device and connect it to pc...

Your system will be flashed on chipset level...

2. Repair fingerprint sensor DIFFICULTY: 3/5

Follow steps on this video: Fingerprint Repair

But instead of holding finger on all test except BLACK RUBBER test, you need to hold it only when testing FLESH RUBBER, do not cover sensor with anything on other tests. And you should get red error saying: FAIL GF ERROR BAD POINT CLUSTER... and now you can proceed with copying data and engineermode to persist via root explorer (in GDrive) just like in the video...

3. Repair IMEI DIFFICULTY: 4/5

Download IMEI repair, open settings and input password: ustest, enable dual IMEI and write MEID as well... apply settings and connect your device,

go to dialer app and enter *#801# enable Diag,Adb and Serial, go to GDrive and download QC Important Driver.zip

Go to device manager and you should see your phone in COM/LPT section, IN2023 or something like that... There could be like two devices IN2023 and you must install this driver on both! Right click on it and select update driver, Browse computer>Let me pick...>Show All> Have disk and now go to qcser.inf_amd64 and select qcser.inf and click OK, from all the drivers from the list you need to select Qualcomm HS-USB Diagnostics 90B6 and now go to IMEI write tool and click Write. Your IMEI should now be written... You can go back to *#801# and disable diag,adb serial and you just need to restart device to reload new IMEI

Sources:

Repar IMEI

Fingerprint Repair