This guide was originally written by chief_os from 4PDA.ru on how to roll back to Oreo, but my network issues wasn't caused by downgrading and still this helped me out so big thanks to the guy from the beautiful Lviv.
I alter this guide a bit, according to what I've done to get my network to work.
Download all the given files:
Follow the steps:
In some rare cases you may still experiencing network problems. If so, check your EFS partition if it doesn't contain some weird looking folders. If yes - just delete them. [need to edit this part later].
I alter this guide a bit, according to what I've done to get my network to work.
Download all the given files:
- Qualcomm Tool QPST_2.7.453.zip - unpack and install
- QualcommIMEIRebuilder.zip (given in this thread)
- daisyQCN.zip (given in this thread) - it contains the file daisy.QCN, which you will need to recover your IMEIs
- Fastboot ROM image of your choice from here
- TWRP Recovery twrp-3.2.3-0-daisy.img - move it to your ADB & Fastboot folder
Follow the steps:
- Remove all your SIM cards from the tray followed by disabling PIN security
- Make a screenshot of your IMEI numbers and store it outside the phone
- Install QPST_2.7.453.0
- Enable USB debugging
- Unlock the bootloader with
and, if you don't want to lose your data, use the instructions with Vol- button given here.Code:
fastboot oem unlock - Reboot with
Code:
fastboot reboot - Go to the dialer and open the diagnostic COM port by typing: * # * # 7 1 7 7 1 7 # * # *
- If the code doesn't give you any feedback, type:
Code:
adb shell su setprop sys.usb.config rndis,diag,adb - Disconnect and connect the cable, then check the Device Manager for a device qualcomm hs-usb qdloader 9092 (COM[port number]). If the device is not there - reconnect again.
- Open QFIL.exe and check what port is your phone on. If you can't see any, click on SelectPort and choose your [port number].
- Choose Tools, then QCN Backup Restore
- Check Enable Multi-SIM, click Backup QCN and wait for the completion of the current backup (if something goes wrong, you can roll back)
- The backup file will be in the given folder
- Run Qualcomm IMEI Rebuilder and select downloaded daisyQCN.qcn file
- Replace IMEI numbers with your IMEIs and click Rebuild
- Run QPST.exe. Choose Restore tab, select the rebuilded .qcn file and click Restore
At this point you might want to check if all is working as it should. If not, proceed:
- Create a backup of the EFS partitions:
- Reboot in Fastboot by:
Code:
adb reboot bootloader - Boot into TWRP by:
and after requesting the password, do not press anything on the phoneCode:
fastboot boot twrp-3.2.3-0-daisy.img - On the PC, type the commands in the given order:
Code:adb shell mkdir -p / sdcard / Backup dd if = / dev / block / mmcblk0p39 of = / sdcard / Backup / fsg.bin dd if = / dev / block / mmcblk0p40 of = / sdcard / Backup / modemst1.bin dd if = / dev / block / mmcblk0p41 of = / sdcard / Backup / modemst2.bin dd if = / dev / block / mmcblk0p42 of = / sdcard / Backup / bk5.bin dd if = / dev / block / mmcblk0p49 of = / sdcard / Backup / persist.img dd if = / dev / block / mmcblk0p50 of = / sdcard / Backup / persistbak.img exit adb pull /sdcard/Backup/fsg.bin fsg.bin adb pull /sdcard/Backup/modemst1.bin modemst1.bin adb pull /sdcard/Backup/modemst2.bin modemst2.bin adb pull /sdcard/Backup/bk5.bin bk5.bin adb pull /sdcard/Backup/persist.img persist.img adb pull /sdcard/Backup/persistbak.img persistbak.img - Click the recovery button when requesting a password, go to Reboot and select System
- Check if your backup files are in the ADB & Fastboot folder
- Reboot the phone in fastboot and type:
Code:
fastboot oem edl - Flash the ROM via the MiFlash utility or via command line flash_all.bat batch file (don't choose flash_all_and_lock!)
- Reboot the phone, go through initial setup and check if your SIM cards are working. If not, repeat steps 7 - 12
- Check Enable Multi-SIM, click Browse and select the rebuilded .qcn file. Press the Restore button
- When done, reboot into fastboot by:
Code:
adb reboot bootloader - Repeat steps 18 - 19
- Run the following commands in turn:
Code:adb shell dd if=/dev/zero of=/dev/block/mmcblk0p40 dd if=/dev/zero of=/dev/block/mmcblk0p41 exit - Repeat step 21 and boot the OS
- Now everything should work just fine.
- In case of anything goes wrong, you can restore your backup .qcn file via QFIL (12 - 13) and then reflash your backups
- Load into TWRP and execute commands:
Code:adb shell dd if = / dev / zero of = / dev / block / mmcblk0p39 dd if = / dev / zero of = / dev / block / mmcblk0p40 dd if = / dev / zero of = / dev / block / mmcblk0p41 dd if = / dev / zero of = / dev / block / mmcblk0p42 dd if = / dev / zero of = / dev / block / mmcblk0p49 dd if = / dev / zero of = / dev / block / mmcblk0p50 exit fastboot flash fsg fsg.bin fastboot flash modemst1 modemst1.bin fastboot flash modemst2 modemst2.bin fastboot flash bk5 bk5.bin fastboot flash persist.img fastboot flash persistbak persistbak.img - Reboot.
In some rare cases you may still experiencing network problems. If so, check your EFS partition if it doesn't contain some weird looking folders. If yes - just delete them. [need to edit this part later].
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