This tutorial is intended for phones with wherein IMEI is corrupted or simply missing. Possible causes include, after flashing imei is corrupted or missing, cannot connect to network or sim cannot be recognized.
1. Send imei.bak to SD card
2. Open M44 Tool , go to engineer model (MTK) – GPRS. (NOTE: phone should be rooted)
3. There you will find the imei back up restore. REMEMBER: a bug may persist wherein if your system is English it will force the system to stop, so please remember to location where you place the imei backup.
4. Change the language to chinese, and enter the M44 tool box again. Click restore number from SD card 2
Note that if you can’t see the imei 1 and 2, all you need is to write new imei 1 and 2 and then restart. You may not write New Imei 2 if it is not included.
Thank you and enjoy.
Source: fastcardtech techsupport