[Tutorial] How to fix unknown Baseband version, null / invalid IMEI & SIM card not detected on Android phone

Quite a number of MTK users have been having this
issue 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:

MP0B_001 Method

1. Download ROM toolbox lite from Playstore
2. Download IMEI.zip (to create a new IMEI file)
then unzip the content of the folder (imei.exe) to a
folder on your desktop
3. In command prompt, navigate to the imei.exe
containing folder you just created on your desktop
* NOTE cd\ then enter (returns to root directory)

Code:
cd.. enter (goes up one
directory)

Code:
cd foldername enter
(navigates to a folder called
foldername)

4. A faster method is to open the imei.exe containing
folder > Hold down Shift > Right-click on an empty
space > Select "Open Command Window here"
5. When you're inside the imei folder in command
prompt, type
imei.exe <15digit_IMEI_1> <15digit_IMEI_2>
eg

Code:
imei.exe 123456789111111
123456789111124

6. Press Enter
7. If both IMEIs you gave are of the correct format,
a file named MP0B_001_NEW will be created.
Rename it MP0B_001.
8. Now you can send it to the sd of your phone
9. Install ROM toolbox lite then go to root explorer
10. In root explorer, delete the existing MP0B_001
file (located @ device/data/nvram/md/NVRAM/
NVD_IMEI) and replace with the one you just
created
11. Long press the new MP0B_001, go to permissions
and tick all 9 boxes at the top then select ok (don't tick
special pernissions)
12. Restart your phone
13. Your SIMs should be detected, IMEI reflect and
Baseband version change from unknown to what it
should be.
* Note that getting this done might not be this direct
due to different scenarios but replacing the MP0B_001
file is the ultimate goal in order to fix the issue.

IMEI Replacement Method

This method involves the use of MTK droid tools and
is only applicable when your SIM cards are detected
but IMEI is invalid or null. To do this

:
1. Download MTK droid tools
2. Download PdaNet
3. Enable USB debugging on the phone then connect it
to the PC (don't enable mass storage)
4. Install PdaNet on the PC with the phone
connected; you should get a message saying drivers
installed successfully.
5. Extract then launch MTK droid tools on the PC
(still with phone connected to PC)
6. MTK droid tools should detect and display your
phones details
7. Click on IMEI/NVRAM
8. Supply the IMEI(s) then click replace
9. Restart your phone if it isn't automatically restarted
10. Your IMEI issue should have been resolved

NVRAM Restore Method

* Note that you need a working phone of the same
model to backup NVRAM first

1. Download MTK droid tools
2. Download PdaNet
3. Enable USB debugging on the GOOD phone then
connect it to the PC (don't enable mass storage)
4. Install PdaNet on the PC with the phone
connected; you should get a message saying drivers
installed successfully.
5. Extract then launch MTK droid tools on the PC
(still with phone connected to PC)
6. MTK droid tools should detect and display your
phones details
7. Click IMEI / NVRAM
8. Click Backup
9. When backup is complete, open the MTK Folder >
BackupNVRAM to confirm that backup was successful
8. Connect the phone with Basebrand / IMEI error
to the PC still with MTK droid tools open
9. Still under IMEI / NVRAM, click Restore
10. Select the appropriate files from the windows that
pop up
11. Reboot the phone once the procedure is complete

ENGINEERING MODE METHOD

1. Download and Install Mobile Uncle then grant
superuser permission
2. Select Engineer mode
3. Select Engineer mode (MTK)
4. Navigate to the Connectivity tab
5. Select CDS information
3. Select Radio Information
4. At Phone 1: Insert the command below then click
Send at command

Code:
AT+EGMR=1,7,"IMEI1"

5. At Phone 2: Insert the command below then click

Send at command

Code:
AT+EGMR=1,10,"IMEI2"

6. Go back to Mobile uncle home screen
7. Click on Engineer Mode
8. Select Engineer mode (Android)
9, Select Phone information
10. Click Turn on radio