Tag Archives: DFU

Downgrade iPhone 3G from iOS4 to iPhone OS 3.1.3

Its time to go back.. Not to the island but on 3.1.3.

iOS 4 made my iPhone feels like a Sony/Nokia one, where I press something and I can have a coffee until I get a response back (you said something about Flash performance on the iPhone?). The worst was when I couldnt even answer a call. The downgrade is so easy and I really didnt felt that there was any risk at all. But hey.. This is Apple’s h/w and s/w so do not blame me if something goes wrong. Please read the whole post 1st before you try it.

Here is the “todos list”:

You need to find and download the official iPhone OS 3.1.3. There is a small chance to already have it in your “USER/Library/iTunes/iPhone Software Updates”. If you use time machine then probably you will have it. The name of the file is “iPhone1,2_3.1.3_7E18_Restore.ipsw” and Finder reports that the size is 239.1 MBs (228MBs on Safari). Now if you don’t have it you can download it from here.

You also need an utility in order to bring the iPhone back to life from DFU mode. (Come on don’t be scared).
I used the one called “RecBoot” . The zip you are going to download contains 2 apps. The only one you are going to need is the “RecBoot Exit Only.app”.

Ready to go..

-You have to put the iPhone in DFU mode (Device Firmware Update or just “coma”). You do that by turning the iPhone off, connect it with the cable to iTunes and then Press the Power and the Home button at the same time. Hold them down for exactly 10 seconds. After that you release the Power button ONLY and you keep down the Home button for another 10 seconds. If you were good in math you are going to get a pop up in iTunes informing you that it detected and iPhone in recovery mode. The iPhone now has a black screen 🙂 (Don’t worry!)

-Restore: Now press ok and under iPhone, on iTunes, you press Restore by also holding down the alt key (in order to let you browse and find the OS you downloaded earlier). Then the restoration process will take place.

In the end of the installation it is more probably that you will get an error message saying “The iPhone could not be restored. An unknown error occurred (1015).” Feel happy cause you did it right!

-Now its time to wake up the phone from the coma. Open the “RecBoot Exit Only.app” you downloaded earlier and click (the only button in there) “Exit Recovery Mode”.

Now your iPhone 3G feels again like the iPhone 3G!

One more thing..

Keep in mind that you can not restore your data from iOS4 to iPhone OS 3.1.3. So if the only back up you have is from the iOS4 you have to setup everything from scratch (like the awesome first day that u got it in your hands!). Again if you have time machine or you kept a back up from when you where in 3.1.3 feel free to restore the device using that back up.
I didn’t so I had to install everything from scratch. Although iTunes did the most of the work for me (syncing apps, iCal, Address Book etc) I like to keep Music and Emails manually managed so I had to set up them again. As for the Maps’ Bookmarks unfortunately I couldn’t find a decent app to back them app so what I did was:
Going through every bookmark on the iPhone app and hit “Share location”. I mailed them to my account and after downgrading my iPhone I added them back by pressing on the link on every email. Not very happy about that but at least I also got back the name of the bookmark I had before, so thats something.

The whole above process should work on windows too since the RecBoot app is available for this “OS” too.

Have fun!