I have found a question online, someone was facing with his Samsung galaxy smartphone, it was not the “Not Registered on networkor No Service problem” It was more like “Waiting for network ” I followed up on the individual, and he said:
I have a Galaxy S3 and I just got and the person I got it from did a factory reset and now it comes up select language and I press English then Start and it goes to a screen that says Waiting For Network… Activation can take a few minutes. Then after a little while it says can’t activate the phone call customer service. So I did and they said they would not unless I had an account with them
The solution to Fix Samsung Galaxy “Waiting for network” can be found below. I have ran some experiment and testing to eradicate the “Waiting For Network Issue on my Samsung galaxy S3.
How to Fix Samsung Galaxy “Waiting for network“
To Fix this problem will need you to access the Network Operation menu. This is a soft network lock on you carrier, and you can simply unlock this the phone by following the method to bellow.
90% of our visitors has found the solution to How to Fix Samsung Galaxy “Waiting for network” by following the step below
Your Samsung Galaxy must be running Android 4.1.1 (It doesn’t work with some Android 4.3 either)
Remove your Sim card
When you select UMTS, you will see another service menu appears
>Open Debug Mode , on the screen appeared Select PHONE CONTROL
>After that select NETWORK LOCK.
>Tab on Select Perso SHA256 Off
Wait for 1 minute
>Press the menu key(Button left of the home button)
>A new option will appear NW Lock NV Data INITIALLIZE , select it .
If you do not see this option then you are not running Version 4.1.1
Wait for 2 minutes then reboot your phone, after, insert your sim card
Samsung Galaxy “Waiting for network” error will be gone when booted