How To Downgrade your iPhone 3G to iOS 3.1.3
Posted 07/30/2010 at 10:00am
| by Susie Ochs
It’s official. Four out of four Mac|Life editors still using the iPhone 3G have said sayonara to iOS 4. Many of its marquee features aren’t compatible with our two-year-old handsets anyway—no multitasking, no nifty orientation lock, not even background wallpaper. And worst of all, it hobbles our once-functional phones until they’re near-useless. Apps crash, or they’re teeth-pullingly slow to open. Download speeds are so slow we feel like we’re back on dialup. The entire OS even crashes back to the Apple-logo screen. It’s just not worth it. So we rolled back. And if you feel our pain, we recommend you do too. Here is everything you need to know.

iPhone OS 3.1.3: It’s the last truly great OS for your iPhone 3G. (Sorry, Apple.)
Difficulty: medium
What You Need:
>> iPhone 3G
>> iTunes (free, apple.com)
>> RecBoot (free, www.sebby.net/443-recboot-final-release/)
>> iPhone OS 3.1.3 firmware image (see Step 3)
1. Check Your Back(-ups)

I’ve got some pre-June 21 backups, but alas they are all for various office iPads.
Not to get ahead of ourselves, but before you restore your iPhone with the older OS, it’s a good idea to consider if you’ll be setting up your newly downgraded phone from scratch as if it were a new phone, or if you’ll be restoring it to a backup. The catch is that you can only OS 3.1.3 backup, not to a backup made after you put iOS 4 on your phone.
iOS 4 came out June 21. So to see if you have any iPhone backups made with OS 3.1.3, navigate to ~/Library/Application Support/MobileSync/Backup and see if any of the folder inside are dated before then. But since iTunes doesn’t keep more than one backup per device, if you’ve synced your iPhone to iTunes after upgrading to iOS 4, you probably don’t have a backup of your phone with OS 3.1.3.
2. Data Dump

Get all your photos into iPhoto, or lose them forever.
So it’s pretty safe to assume you’ll be setting up your iPhone running OS 3.1.3 as a new iPhone. In that case, it’s crucial to get any important info off your iPhone before you attempt the restore. Sync any Notes to your Mac, or email them to yourself. Take screenshots of your home screens so you can set them up the same way later. Take screenshots of your email account pages if you think you’ll need help setting them up again (we always need help remembering what to enter for our Microsoft Exchange account, for example). Transfer those screenshots and any photos you’ve taken to iPhoto.
3. No Data Left Behind

iTunes can transfer iTunes Store and App Store purchases onto your Mac.
If you buy music or apps directly on your phone, connect it to your Mac and choose File > Transfer Purchases from [Phone Name] in iTunes. You’ll also lose your SMS and MMS messages, so take screenshots of those, or follow the instructions at insend.de to back them up as a PDF, CSV, or XML file. Basically, you need get every scrap of information on your iPhone onto your computer somewhere, because you’re about to wipe your iPhone completely. One more note: Any apps you put back on your restored phone will behave as if you’ve never used them. So if you use apps with accounts tied to them (Facebook, Flickr, Instapaper, etc.) you might want to jot down your account info. And sadly, you’ll lose your progress in any games, plus lose access to the iBooks app, which requires iOS 4.
4. Downloads

These are the two items you need.
Now that you’ve come to terms with what restoring will do to your phone, it’s time to get started. First, head to iclarified.com/entry/index.php?enid=750 and download the 228MB disk image of the iPhone OS 3.1.3 firmware for the iPhone 3G (or the iPhone 3GS, if that’s what you’re restoring). The exact filename is iPhone1,2_3.1.3_7E18.Restore.ipsw. Save it to your Desktop. Then download and install an app called RecBoot from www.sebby.net/443-recboot-final-release/. RecBoot requires 10.5 or later and an Intel Mac.
5. DFU Mode

When you see this dialog, you’re in DFU mode and can proceed to Step 6.
Next, put your phone in Device Firmware Update mode. Plug the phone into your Mac, and turn the phone off by holding the Sleep button and using the “Slide to Power Off” slider. After it’s off, hold down both the Sleep button and the Home button while you slowly count to 10. Then release the Sleep button but keep that Home button pressed down. After a few more seconds, iTunes will throw up this window. If that doesn’t work, repeat this entire step until it does.
6. Restore

Option-click Restore, choose the 3.1.3 firmware, and watch the progress bars go.
Dismiss the “iTunes has detected an iPhone in recovery mode” dialog. Now click the iPhone in the iTunes sidebar and Option-click the Restore button (as in, hold down the Option key while clicking the Restore button. If you're using Windows, hold down Shift). You’ll be asked to choose a file. Select the iPhone OS 3.1.3 firmware file you downloaded in Step 4. You’ll see an extracting software progress bar, then a preparing iphone for restore progress bar. Your iPhone will have a progress bar too while it’s being restored. expect this to take 10 minutes or so, maybe more. Don’t dismiss the error dialog that pops up when it’s finished.
7. Enter RecBoot

Don’t dismiss the error message until after RecBoot does its thing.
To repeat, when you see the error dialog “The iPhone could not be restored. An unknown error occurred (1015)” DON’T DISMISS IT YET. (At this point, your iPhone is showing a “Connect to iTunes” screen.) Instead, go to your Applications folder, where you installed RecBoot. Look in the RecBoot 1.0.2 folder, and you’ll see a ReadMe file, plus applications called RecBoot and RecBoot Exit Only. Launch the latter, RecBoot Exit Only. It displays a large Exit Recovery Mode button. Click that. The Connect-to-iTunes screen will disappear from your iPhone, and you can now dismiss the error message in iTunes.
8. Set It Up

No, no, no, no. Don’t ask me again. Cancel.
The next dialog will be about helping Apple improve its products. Agree or disagree at your leisure, and then after another minute or so your iPhone will display the “iPhone is activated” message, and iTunes will launch the Set Up Your iPhone screen, which asks you if you want to set up as a new iPhone or restore from a backup. As explained in Step 1, you most likely won’t have a backup to restore to, so go ahead and set it up as a new iPhone.
Your “new” iPhone will be running fresh as a daisy, and ready for you to refill with apps, music, photos, contacts, and all that other iPhony goodness. The next time you get a message about updating to iOS 4.0.1, check the box for “Don’t ask me again” before you say no.