Sometimes, when you attempt to upgrade or install a new ROM on your Android device, you might get an invalid IMEI error. In which case, there will be no signal on your phone.

Installing a new ROM is not the only cause of an invalid IMEI as we will see later in this text. You will find a detailed guide on how to fix an unknown BaseBand version for your MTK device here so let's jump right into it. Shall we?

What Is IMEI

IMEI stands for International Mobile Equipment Identity. Basically, it is a bunch of numbers unique to every Android device that can be used to identify such a device. Kind of how everyone can be identified by their unique BVN number or social security number.

Because of the unique nature of the IMEI, it can be used to identify a particular device. It can also be used by the authorities to blacklist a mobile phone from accessing a particular network or to block stolen mobile phones.

Causes Of Invalid IMEI

There are several reasons why a smartphone will display an invalid IMEI error. The most common reasons include:

Performing a Factory reset wrongly.
Flashing a custom or stock ROM improperly.
Manually changing your device IMEI

All of the above can cause an IMEI error on your Android phone. When this happens, it becomes difficult to make and receive calls, send and receive text messages, and even accessing the internet using mobile phone data becomes a problem.

Irrespective of what caused an Invalid IMEI on your Android phone in the first place, this article contains the solution to fix the problem and get your smartphone working back again.

How To Fix An Invalid IMEI On Android

There are several ways you can go about this, and it works for both rooted and non-rooted devices.

We will need a valid IMEI in other to get this to work. To get one, open your phone battery cover to see your device IMEI number. If this is not possible, probably because your device has an inbuilt battery, then you can also look at the receipt of your mobile phone. The IMEI number is usually written there or you can check at the back of the pack your phone came with when you first purchased it.

If your MTK device is dual SIM, then you will find two IMEI numbers, One for SIM slot 1 and the other for SIM slot 2. Copy them down because we will be making use of them shortly.

Also, before proceeding. Dial *#06# to display your current Smartphone IMEI. If it displays invalid IMEI or nothing shows up, you can skip this paragraph otherwise, Write down the IMEI somewhere separate from the first number and keep it safe.

The reason for doing this is because, if something goes wrong, you will be able to revert back to your current IMEI. Iike I said earlier, we are going to look at how we can do this for both rooted and non-rooted devices. For both cases, I will be using the simplest method for solving this issue.

How To Fix Invalid IMEI Without Root

If your Android device is not rooted then this method should work for you. To Fix Invalid IMEI without Root.

Go to the Google Play Store, download and Install " MTK Engineering Mode".
Launch The application and select "MTK Settings" from the menu.
Now slide left to go-to the "Connectivity" Menu.
Now click on "CDS Information" followed by "Radio Information".
After "AT+" type EGMR=1,10,""
Now write the IMEI number you want in between the double quote. for example. AT+ EGMR=1,10,"725273656789643". This is for SIM 1.
If you have a dual SIM phone then do the same thing for SIM 2. After "AT+" type EGMR=1,7,"". And enter the IMEI between the quotes.
Then send the command.

At this point, you are all done. All you have to do now is to reboot your device. Alternatively, you can turn ON Airplane mode for at least 5 seconds before turning it back off. Now Check your new IMEI by dialing *#06#.

Fixing Invalid IMEI For Rooted Device

If your MTK device is rooted then it becomes incredibly easy to change and validate your IMEI. To Fix Invalid IMEI for a rooted device:

Download Chamelephon by clicking here
Install and launch the app on your Android Phone then grant it Root Access.
Now insert the IMEI number for SIM 1 in the first box and the one for SIM 2 in the second box if you own a dual SIM phone and then click on "Apply new IMEIs"
Now Reboot your phone and dial *#06# to check your IMEI.

How To Fix Unknown BaseBand Version On MTK Device

Unknown BaseBand usually comes up when flashing a custom ROM goes wrong. When this happens, you will not be unable to make or receive calls with your phone because your mobile phone will have a hard time recognizing your SIM. Unknown BaseBand can easily be fixed by following the steps below

Download and install es file explorer on your device.
Open the mobile app and grant it Root Access.
Now click on Root Explorer from the menu and then "Mount As".
Click on "Mount As R/W" then navigate to device > data.
At this point, you will find a folder with the name "NVRAM". Delete the folder and then reboot your device.

Method 2

If you are having a hard time following method one above then you can try this instead.

Requirements:

Here are some of the tools you will need to fix unknown baseband.

A Computer
An MTK Device
MTK Droid tools (download it here)
IMEI number
USB ADB drivers
NVRAM backup (This should be from the same model of your MTK device.)

Procedures:

First, download and extract MTK Droid tools on your computer.
Now download USB ADB drivers for Android.. install and launch the app.
Go to your phone setting and click on developer options and then enable USB Debugging.
if you can't find the developer option. Go-to Settings > System > About phone > Build number. Click on "build number" three times until it displays "you are now a developer" to enable developer option.
Launch the MTK Droid tools on your computer
Now connect your phone to your computer via a USB cable.
Click on the "ROOT" button and then click on IMEI / NVRAM
Click the "Restore" button and Open NVRAM back up
from here, you can now change your device IMEI from the option displayed on your screen.
you can now insert your valid IMEI and then click on "Replace IMEI".
Reboot your device and then dial*#06# to check your new IMEI.

SME Arena

How To Fix Invalid IMEI And Unknown BaseBand