Quite a number of MTK users have been having this issue unknown Baseband version, null / invalid IMEI & SIM card not detected on their MTK devices after flashing one ROM or another; something i call the 'Custom ROM fever'. This issue is mostly caused by wiping / corruption of the data partition. The Baseband and radio (for network signal) are controlled by the NVRAM (located in data/nvram/md/NVRAM/NVD_IMEI) and a file called MP0B_001.
Once this file is missing or the NVRAM partiton is corrupted, your phone's IMEI and radio functionality cease to exist. There are several methods to fix this:


# See the video tutorial below on How to fix unknown Baseband version, null / invalid IMEI & SIM card not detected

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