>Open up dialer and enter *#06# to check your IMEI number, if you see IMEi Null then you need to reconfigure the settings to fix the no signal or not register on network problem on your Galaxy Phone
> In the dialer , type- *#197328640# or *#*#197328640#*#*
>You will be prompt into the Command mode, On the screen provided , Select on Common , normally option 6
> Now Select (FTM) Option 1
>FTM is for debugging and testing .,(Field Test Mode)
>If (FTM) is on, you will have to turn this OFF
>As soon as your turned this off your NULL or altered IMEI number will be restored
>(Important) Without leaving the Command screen press the Menu key, the button thats found left of the Home button .
> Select Key input and enter option 2. In this case you want to turn it off
>Wait for a minute , this will turn your FTM OFF
> Remove your battery and sim card for 2 minute
>Place your battery inside you Samsung galaxy Phone, (important) do not place your sim card in
> When the phone is booted, enter the command mode again dial *#197328640#
>Select the Debug Screen , normally option 1
>After that, select phone control, option 8
>Click on nas control , option 3
>Now, on the screen provided, click RRC(HSDPA) ,option 5
>To Fix not registered on network or Null IMEI # , click RRC revision , option 2
>Now, click on the released your phone is , here we will choose option 5 (HSDPA only)
>Final step to fix Null IMEI not registered on network for Samsung Galaxy is to turn off your phone then insert your sim
