When I followed some of the tutorials on the net to jailbreak my iPhone, I found that there is a critical information that some tutorials do not mention if you are a AT&T customer with an activated iPhone. That is if your iPhone has been activated with AT&T’s SIM card, you don’t want to check the option that says “Activate the phone“. Here is a screen shot of the PwnageTool 2.0.
This option is under General section when you use PwnageTool in Expert mode. If you use PwnageTool in Simple mode, make sure you answer “Yes” to the question “Are you a legit iPhone 3G user?“.
What if you have checked the option “Activate the phone”? Chances are your iPhone’s phone function will not work at all after you apply the custom built firmware. What can you do about this situation? You can try to use iTunes to restore your latest backup to your iPhone. If the phone is still not working, the last resort is to restore it using the original firmware that you downloaded from Apple.