j700t

i have j700t and my imei is 000000000000
i tried everything but failed
i tried efs
modem file
nv file and other effort but failed and when i write imei
show this msg
Detecting MODEM... OK
Reading MODEM... OK
Calculating... OK
Writing zTool... OK
Initialization zTool... OK
Running zTool, please wait... OK
Reading data... error (1 19)
Initialization zTool... OK
Running zTool, please wait... OK
Reading data from phone... error (0)
Try downgrade modem if possible