Jailbreaking / unlocking the 3G iPhone on 4.0.2 firmware using redsn0w
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Who is this guide for?
I used iTunes 9.2.1 (5).
I used OS X 10.6.4.
Thanks again go out to the iPhone Dev Team for providing this amazing, and FREE program for
customizing the iPhone. You can visit their website here,
and their blog here.
You can read their
notes regarding 4.0.2 firmware here.
Download 4.0.2 firmware from Apple here:
You should now have this icon on your desktop. If it ends in .zip, rename it to end in .ipsw.
Note: Safari likes to open "safe" files by default. You must turn this feature off for this download
to work correctly. Click "Safari", select "Preferences", from the "Geneal" tab uncheck the box that
says "Open "safe" files after downloading". Otherwise just use Firefox to download this firmware
Plug in your iPhone to iTunes and press the option key on your Mac, then click the restore button.
Navigate to your 4.0.2 firmware file on your computer. You are restoring to 4.0.2 firmware. You do
not want to update as updating causes problems with flash storage space disappearing in jailbroken
Various messages will appear while the iPhone is restored.
When this finished I was at the slide for emergency screen on the iPhone (because I left my
T-Mobile SIM in).
I also received this warning message from iTunes.
Download redsn0w 0.9.5b5-5 (or newer) from the iPhone Dev Team
Download 4.0 firmware from Apple here:
You should now have these two icons on your desktop. If your firmware file ends in .zip, then edit
the file name to remove the .zip so that it ends in .ipsw.
Double click the redsn0w.zip file and the application icon will appear.
Drag the redsn0w.app file into your Applications folder.
Launch redsn0w. Click the Browse button.
Navigate to where your 4.0 firmware file is, select it and click Open.
If you blink you will miss the lines of text that say: Processing firmware, and IPSW successfully
identified. Click the Next button.
A pop up will appear and display several messages quickly.
There are several options. Make your selections and click Next. Note: enabling multitasking on the
3G really slows it down.
Make sure your iPhone is off, and plugged into your computer with the USB cable. Click the Next
Instructions for entering DFU mode will appear. They start right away and go very quickly so try to
keep up! First hold down the Power (sleep/wake) button for three seconds.
Keep holding on to the Power button, and press and hold the Home button for 10 seconds.
Continue holding the Home button, and release the Power button.