SAM is a jailbreak app that allows iPhone users to unlock their iPhone so that they can activate and use a non-stock SIM card which is not supported by your existing carrier. Since the release of the new SAM, Apple is trying to fix the activation server bug which SAM uses to get the activation ticket. This means future users may not able to unlock iPhone with SAM. If you have unlocked your iPhone with SAM, please backup your activation ticket for further use. You can try to use the RedSnow tool to save your iPhone activation ticket.
With the saved activation ticket, you can unlock you iPhone again when you accidentally restored your iPhone firmware. If you restored the iPhone firmware, the saved activation ticket will allows you unlock iPhone again. Follow these steps to unlock iPhone with saved activation ticket:
1. Insert the SIM card which is not supported by you existing carrier.
3. Click the “Edit” button on the right top. Enter to the edit mode. Select “Lockdown” folder.
4. Use “Compress” function to make the “Lockdown” into a zip file.
5. Confirm your compressed package has been successfully created. If yes, delete “Lockdown” folder.
6. Copy the saved activation folder to your iPhone. Then uncompress the created zip package.
7. The unarchived file should be placed in “Documents” folder.
8. Click “Edit”. Copy the “Lockdown” folder to /var/root/Library
9. If you installed SAMPrefs, please delete file “com.bingner.sam.plist” under /User/Library/Preferences folder.
10. Restart you iPhone. You will be able to connect to wireless. It means you have unlocked your iPhone again with the saved activation ticket.
This tutorial is applicable for iPhone 3GS, and iPhone 3G, iPhone 4 and the brand new iPhone 4S.
Note: This solution is for Jailbreaked iPhone. Make sure you have backuped you SAM activation ticket.