Here is a guide to repair IMEI definitively
First of all Download our latest driver pack for mediatek devices:
You will need later on.
Download then the Sn Write tool
Start the software and select the comport USB VCOM, The target as SMARTPHONE like in picture:
Click on System Config, then select Imei, Dual Imei like in picture below:
In the same windows, click on MD DB1 and search for the proper Database File (it comes with the complete firmware of your phone)
The file is similar to this:
Always in same window, click on AP DB and select proper file, always coming with your firmware (is like APDB_MT6592_S01_KK1.MP1_)
Then close the window clicking on OK
You will see a requester like this one:
Configure like in picture and click on OK
Almost done! Now you can click on start
You will be prompted for imei like:
Insert your IMEI, click on ok and connect you mobile TURNED OFF and with battery inside.
The phone should turn on and stay on logo. At this point, if you do not have Metamode drivers installed, you should go on your device manager and find the Mediatek cdc entry and install the drivers you previously downloaded from this page.
If you have never installed those drivers before, probably you will need to repeat the entire procedure from beginning