This article is part of our iPhone 101 series in which we post about the most basic questions new or inexperienced iPhone, iPad or iPod touch owners regularly ask us. If you got yourself a new iPhone 4S and want to put it in DFU mode, follow this guide closely as it contains all the steps you need to know in order to put iPhone 4S in DFU mode, in great detail.
Now why would you need to put your iPhone 4S in DFU mode any way? There can be a number of reasons for that. First and foremost, if you want to do a clean install of iOS 5 on iPhone 4S and the procedure you're following explicitly mentioned you to first put your iPhone 4S in DFU mode before installing iOS 5, then its obviously clear by now that DFU mode is a pre-requisite. Such need can arise if your iPhone 4S is stuck in recovery loop or the screen has simply gone blank without any reason even though the device itself has plenty of charge left.
Another reason as to why you need to learn how to put iPhone 4S in DFU mode is the fact that in a couple of months from now it is going to be possible to jailbreak iPhone 4S, as we already know jailbreak developers have got iPhone 4S jailbreak covered. In that case, you would need to put your iPhone 4S in DFU mode as certain jailbreak procedures require you to first put your device in DFU mode before proceeding. DFU mode will also be required when trying to preserve baseband or restore to an older iOS firwmare version on iPhone 4S.
How To Put iPhone 4S In DFU Mode:
Follow the instructions mentioned below carefully. Do keep in mind that there are no repercussions of putting your iPhone 4S in DFU mode. It does not harm your device in any way and even if DFU mode is entered, the device can easily be rebooted through a hard reset even if no procedure has been performed.
Step 1: Power OFF your device by first holding the Sleep/Wake key until Slide to Power Off appears.
Step 2: Plug your iPhone 4S in the computer. As previously mentioned, you will need to enter DFU mode during any of the procedures mentioned above. In that case a relevant program will be open on your computer and it will prompt you as soon as your device enters DFU mode. After you've powered OFF iPhone 4S and plugged it in the computer, proceed to the next step.
Step 3: Press and hold the Sleep/Wake key for 3 seconds
Step 4: Now press and hold both the Sleep/Wake key and Home key for 10 seconds
Step 5: Release Sleep/Wake key but keep holding Home key until the relevant programs prompts you that iPhone 4S is now in DFU mode. The iPhone 4S screen will be completely blank when its in DFU mode.
That's it. These are the five simple steps you need to learn about how to put iPhone 4S in DFU mode. You shouldn't face any problems but in the unlikely event that you should, simply drop a comment below and we'll help you out.