My Galxay Grande Prime can't connect to 3G anymore I used to connect using 3G without any problem. But suddenly the 3G connection is not working anymore.

Problem:
The networking Symbol "H" appear for few seconds (2s-3s) and they disappear and it keeps appearing and disappearing as long as the 3G is on, I tested that during those few seconds the network works fine.



Note that the WIFI works fine.

What I have tried:


Reboot.
Switch-off and Switch-on 3G.
Restore default settings.  


What are the options that I have ?

Android 4.4.1 
Galxay Grande Prime
The sim card was broken, I tried another sim card and it works fine.