Make sure your z3x box is updated

step 1 : open z3x

step 2 : download

step 3 : turn on mobile type *#123580# type 9 then 6 then 2 it will go into samsung qualcomm mode

step 4 : plug in usb cable to mobile* install drivers using the download link

step 5 : make sure usb cable is inserted to mobile

step 5 : type *2767*3855 will give you full reset while the cable is inserted

step 6 : chose com port modem then quickly press UNLOCK BUTTON

This method has been tested on 40x samsung z150