official firmware 4.4.2 then reset efs and repair imei like this
1-
Select Supported Model From List
2- Put Your Phone In Download
Mode
3- Reset Default EFS
4- Select Comport Use UART
Cable
5- Chose Supper IMEI
6- Select Repair IMEI +
UNLOCK
7- Do Factory Mode
(Further Network and 3g
Problems)
8- Select Comport Use UART cable
9- Dial *#7284# and
choose UART -> MODEM and Qualcom Setting DM+MODEM+ADB
10- DIAL
*#0808&# Select DM OVER UART
11- Do 3G NETWORK REPAIR