Here is a lengthy way to get this working on a EU 9 Pro with WORKING SIM card. I just completed my first phone call! Only do this if you know what you are doing and if you are familiar with the concepts of flashing ROMs, using fastboot to flash partitions and possibly using the MSM tool to restore your device in case something goes wrong. I told you.
Steps to switch from OOS>COS on non-chinese OnePlus 9 Pro. Credits to: Telegram user
SamuraiTronVC
Note:
This whole process will wipe your data.
1. Install Android
A12 Beta 1 by OnePlus via Local Upgrade.
2. Once booted into A12 Beta, install the
custom Local Update APK that they provide.
3. Install the
ColorOS Dowgrade package and reboot.
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Here is how to fix the missing network on 9 Pro. I tested it with my own LE2123 EU 9 Pro, but since the A12 DP is working on IN and NA versions as well, should work for everyone. I updated to the latest ColorOS build after step 3, A.08. Don't know if that is required, but do it anyways. The phone has been behaving a bit weird after doing this - e.g. boot loops once, but then it works etc. Not sure if it has to do with steps 4-6, but proceed with caution. Credits to: Myself.
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4. Extract the modem.img from the A12 DP using Payload Dumper. I did it already and you can download it
here, but feel free to extract the .img yourself.
5. Unlock your bootloader:
fastboot oem unlock
6. Flash the modem.img:
fastboot flash modem modem.img
guide!
. After you flash Color OS, head on over to apkmirror and download the play store or any apks of your choice. Color OS has google play services baked. Also get the Gboard, Color OS keyboard is completely for Chinese users.
