How to put the iPhone into DFU mode.


To put the iPhone into DFU mode so you can do an iTunes firmware restore follow these steps:
Step OneOpen iTunes and connect the iPhone to your Mac.








Step TwoPress and hold the Home button and the Sleep/Wake b
utton at the same time.



Step Three
After exactly 10 seconds release the Sleep/Wake button. Continu
e holding the home button until you iTune
s pops up a message telling you that it has detected an iPhone in recover
y mode.











The iPhone screen will remain black like this:













It may take a few attempts to get your iPhone into DFU mode. Generally, I hold down both buttons then release the Home button just before I think the Apple logo would appear. If you are still holding both buttons down and you see the Apple logo you are holding them down for too long!