DFU Mode

Also called Device Firmware Upgrade Mode.

This allows the S5L8900 to be restored from any state. It resides in the VROM and is vulnerable to the pwnage 2.0 exploit.

You might use iNdependence on Mac OSX to set your phone in this state (iTunes 7.7.0 is not supported yet), or use the manual procedure:

Method 1

 * Switch off phone
 * Hold home button and power button simultaneously to turn on
 * Hold them both around 10 secs, then let power button go and keep home pressed until screen flashes and stays "black" but lit

If the Restore Logo is present on the screen, you are in restore mode, NOT DFU.

Method 2

 * When your phone is switched on and connected to iTunes hold home button and power button simultaneously until it switches off (ignoring the red 'switch off'-button in between)
 * wait approx 4 seconds
 * release the power/mute button and keep home pressed until iTunes pops up a message it had found a phone in restore mode

Your phone should have a blank screen, which is DFU mode. If you should see a link symbol on your phone, this is restore mode and you failed.