How to Repair IMEI:
1. Power on the phone and enable "USB Debugging" option.
2. Connect phone to pc via USB cables.
3. Dial(*#*#717717#*#*), Enable Qualcomm Diag port.
4. Press "Scan" button to confirm phone connected.
5. Press "EraseIMEI" (or Press "EraseNVM")
6. Repair IMEI
7. Repair Network

Keywords: XiaoMi, IMEI Repair, Baseband Unknown, No Network, MI 4C