WARNING:
This tutorial will show you how to put your iPhone/Pod Touch into DFU
mode. Please try this at your own risk, as I am not responsible or will
not be held accountable for any damages done to your phone. Although
there may be a resolution to almost all errors, please read the
instructions carefully when downgrading so you won’t encounter any
problems along the way.
DFU mode = Device Firmware Update mode
DFU mode is a mode where the iPod Touch/iPhone will be made to force a
restore of the firmware into whatever version firmware it is given.
Getting your iPod Touch/iPhone into DFU mode is somewhat tricky, and it
may require some patience/practice because timing is essential to get it
to DFU mode and not into recovery mode.
1. First, Open up iTunes, plug in your iPod Touch/iPhone to the CPU's
USB port. Turn on your CPU's speaker and make sure it is loud enough
that you can hear it.
2. Hold down the Home button (top left for iPod Touch and top
right for the iPhone with the screen facing you) and the Power
button (located on the front bottom of your iPod Touch/iPhone)
simutaneously, until the screen goes black and the device turns off.
(past the red slider/slide to power off screen)
3. Now let go of the Power button, but continue to hold the Home
button. Your iPod Touch/iPhone should have turned off and the screen
should not be on.
4. After around ~10-20 seconds, you will hear a noise (beep/ding) from
your CPU as if it had just recognized a new hardware device, now iTunes
should recognize it in DFU mode.
5. After iTunes recognizes the iPod Touch/iPhone, let go of the Home
button otherwise it will go into recovery mode and you will have
to do the entire DFU process over again.
6. You will know when you have put your iPod Touch/iPhone correctly into
DFU mode when the display is blank and that you do not have anything on
your device.
And you are done, now you can install any iPod Touch/iPhone firmware on
to your device via the iTunes SHIFT recovery method.