Getting the idea from this thread
https://xiaomi.eu/community/threads/poco-f5-pro-call-problems.69144/
I've finally made the phone call works on my Chinese Mainland version Redmi Note 12 Turbo with EU Marbel rom.
Here are the steps:
1. extract the
modem.img from Redmi Note 12 Turbo China stock rom
marble_images_V14.0.19.0.TMRCNXM_20230426.0000.00_13.0_cn_5fc5692104
2. download the
xiaomi.eu_multi_MARBLE_V14.0.19.0.TMRCNXM_v14-13.zip and unzip it to a folder
3. use the img file from 1 to replace the same name file under the unzip folder -> images
4. reboot the phone to fastboot mode, and connect it to PC
5. run the
windows_fastboot_first_install_with_data_format.bat script under the unzipped folder, as I'm running a windows system
6. wait for the process completed then reboot to system and setup the phone.
I called my friend successfully and have a talk about 2 mins, also ask for a call back and talked for another 2 mins, it worked well and no more Mobile network not available error.
After going through from Chinese ROM -> GLOBAL ROM -> XIAOMI.EU, I'm sure that I love the XIAOMI.EU ROM most. Thank you very much.
I will keep experiencing my modified EU rom.