iPhone 3G S: Restoring "forbidden" firmware

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Step 5.

On your Mac, go to your Applications folder, then go into the Utilities folder. Launch the program called Terminal.app. Enter the following into the Terminal window that opens:



Now we'll use TinyTSS to take the place of Apple's server by verifying the ECID SHSH for your iPhone. It is important to disable any other servers using port 80. I had nothing conflicting on my Mac by default. Enter this command into the Terminal:



Note: I blurred part of the filename. You will be prompted to enter your system password.




You may have to allow the program to communicate through any firewalls.





You will then receive output from the program.

Step 6.

I then opened a second Terminal window. Click Shell, New Window, Basic.




Enter this command to edit your hosts file: (you may be prompted to enter your password)






Your hosts file should look something like this.




Go to the bottom of the file and enter the following line:



Your file should now look like this.




When you are done, click File, then select Save.

Step 7.

I opened a third Terminal window and entered the following:



It should respond: PING gs.apple.com (127.0.0.1): 56 data bytes. If it does not say this, then you haven't edited your hosts file correctly. If it does say this, you can now restore to the version of firmware that matches your shsh file(s) using iTunes. If it is pinging like it should, you can then close this Terminal window.

Step 8.

Launch iTunes. Turn your iPhone off. Hold down the Home button on the iPhone and plug your USB cable into the iPhone. You will see the connect to iTunes graphic on the iPhone.




iTunes will display a pop up message about recovery mode. Click OK on this message.




Hold down the option key on your Mac and click the Restore button in iTunes. Navigate to the firmware file you want to restore to. Select it and click Choose. Make sure you are restoring to a custom firmware file!




Now simply wait for the restore process to finish. When iTunes prompts you to set up the phone, it's best to set up as new so you don't have any battery issues, et cetera.




iTunes will now confirm you are on 3.1.2 firmware. Congrats, you beat the system!




Here's my About screen now. Back on 3.1.2 with the same 4.26.08 modem firmware. Note: I always erase my serial number, Wi-Fi address, Bluetooth address, IMEI and ICCID for privacy reasons.




Now just unlock with ultrasn0w if on 4.26.08, or use blacksn0w if on 5.11.07.




And I'm back in business.




iTunes will now display the phone number field when unlocked.




Note: If you are downgrading your firmware, then you may need to restore your iPhone two times. The first time it should fail with "An unknown error occurred (1015)". The second time you will receive the same error message. Note: If this does not work, try again, but using DFU mode instead.