G900F no signal after writing cert file

I received a G900F with 3g problem but a signal is good and after writing a cert file the phone lost signal .

I tried a many cert file but the phone still without signal

help me please to solve this problem


Operation: Write CERT
Selected model: SM-G900F
Selected port: COM10 Z3X BOX Serial Port
Software version: 23.9

Checking certificate file... OK
KEY ID: 0478
Waiting ADB device... OK
Reading phone info...
Model: SM-G900F
Android version: 4.4.2
Product code: Not Active
Phone version: G900PVPU1AND2
PDA version: G900FVPU1AND2
CSC version: G900PSPT1AND2
CSC country code: USA
CSC sales code: CHN
HW version: G900P.04
Phone S/N:
Modem board: MSM8974PRO
RF cal date: 2014.03.26
IMEI: ****************
Initialization AT RIL... OK
Bypass MSL... OK
Checking for compatible phone and cert... OK
Phone KEY ID: 0478
Writing CERT... OK
Checking CERT status... OK
Rebooting phone... OK

Done with Samsung Tool PRO v.23.9