DFU (Device Firmware Upgrade) mode is not the same as restore mode. DFU mode bypasses the current OS installed and allows you to upgrade or downgrade your OS. If you are getting errors trying to restore in iTunes, DFU mode is very likely for you.

DFU mode is not recovery mode. Recovery mode has a picture that says connect to iTunes. In DFU mode, the iPhone screen backlight is not even on and the display is blank. If you have anything on your display you are not in DFU mode.

This is how to achieve DFU mode. You can do it on every phone:

Method 1)

• Attach the phone to the pc
• Turn the phone off
• Hold power and home together for *exactly* 10 seconds
• Release power but keep holding home until the pc beeps as a USB device is recognized.
• At no point will the display come on. Now your restore should work.

Having problems? Try adjusting the 10 seconds to be slightly less like 9 seconds, then 8, then 7. It’s a tricky timing but you will eventually get it.

Method 2)

• Hook up the phone powered on to the PC
• Now hold home / power until the phone turns off and keep holding for 10 seconds. If the phone ever turns on during this phase,start over and hold for less time.
• Now release  power and continue holding home until the PC recognizes the phone.
• I don’t like this method as much because there are “rumors” that it may cause some 1604 errors in the restore. I am not convinced of that though.

Method 3)

• Attach the phone to the pc
• Turn the phone off
• Press and hold power. Keep holding power. As soon as you see display on the screen of any sort press and hold home.
• Hold power and home together for *exactly* 10 seconds
• Release power but keep holding home until the pc beeps as a USB device is recognized.
• At no point will the display come on. Now your restore should work.

Having problems? Try adjusting the 10 seconds to be slightly less like 9 seconds, then 8, then 7. It’s a tricky timing but you will eventually get it.

Have MAC OSX 10.5.6 or aMAC Book slim? You have a problem entering DFU mode. Here is an easy fix from the dev-team blog:

1. You will need an account with ADC (Apple Developer Connection) this is free and takes a few minutes to sign up, you should read the terms and conditions carefully and you should only sign up if you are thinking of developing applications in the future – http://developer.apple.com/mac/
2. Download the disk image “IOUSBFamily Log release for Mac OS X 10.5.5 Build 9F33″ (yes, that is a 5 in 10.5.5 – this is a developer debug package of the USB kernel extension).
3. Install IOUSBFamily-315.4.1.pkg from within the disk image
4. Reboot your system!

Click HERE for current jailbreak status