How to Downgrade Your iPhone 3.0 OS

Lots of us have been using the iPhone 3.0 beta full-time. Now we’re rolling back, because it is decidedly NOT ready.

Now, we’re not saying we’re surprised, or angry, or anything. It’s beta software, and beta software is by definition not ready for everyday use. But in the pursuit of the latest and greatest thing, we all have learned that a little bit of inconsistency or crashiness is often a fair price to pay for being on the cutting edge.

Not so in iPhone 3.0. It’s slow as hell, locks up on everything from launching an app to entering a phone number on the numeric keypad, sucks down battery life like an alcoholic who just found his first bottle of MD 20/20 in days, and so on. Add to that a lack of support for MMS as of yet and no apps to take advantage of the background notifications, and you have a fairly useless upgrade, right now. So let’s roll it back.

Note: Your iPhone 3.0 OS backups (your phone settings, unsynched photos, text messages, etc) will not be compatible with 2.2.1 once you go back down. So make sure you have a backup from the 2.2.1 days to restore from, or else you’ll be starting from scratch.

iPhone EDGE

If you’re running OS X 10.5.6, you’ll need to do the USB DFU fix outlined in our jailbreaking guide before proceeding.

1. With your phone plugged in, put it into DFU mode by holding both the power and home buttons for 10 seconds, then releasing power and continuing to hold down home until iTunes recognizes a phone in “recovery mode.”

2. Download the 2.2.1 firmware .ipsw file from Apple. Hold down option (Mac) or shift (Windows) and click on restore. Choose the stock iPhone 2.2.1 file you just downloaded.

3. Let it do its thing, and you should be in business. Restore your backup should you have one, and proceed to jailbreaking if you want to.

iPhone 3G

On the iPhone 3G, the 3.0 software flashes the baseband (the chip that controls voice and data network traffic), which confuses iTunes when you try to downgrade. So you have to jump through a few more hoops to downgrade your 3G, but it’s still easy enough.

1. Follow the first two steps above for iPhone EDGE, only using the iPhone 3G 2.2.1 firmware package of course. Again, OS X 10.5.6 users will have to do the USB driver switcheroo detailed above.

2. When it’s done restoring, you’ll get an error message that looks like this:

As long as it’s a four-digit error number like 10xx, don’t worry, that’s just iTunes telling you it’s confused by the updated baseband on your phone. Everything will work fine, but unfortunately your phone will be stuck in restore mode until you jailbreak it, which is what we’re doing next.

3. For Mac (Windows users skip to step : Download a utility called iRecovery. This tool forces your phone to reboot out of restore mode, which is necessary for the QuickPwn jailbreak software to recognize it.

4. Go to the terminal and change to the iRecovery directory, wherever it is on your system, and type these two commands:

chmod 755 libusb-0.1.4.dylib

chmod 755 iRecovery

5. Next, copy the “libusb-0.1.4.dylib” file to the /usr/local/lib directory on your machine (you’ll have to shift-command-G to go to this folder in Finder).

6. And finally, with your iPhone plugged in, go back to Terminal and type:

./iRecovery -s

You’ll get a prompt, where you should then type “fsboot” (no quotes) and hit enter. If nothing happens after 10-15 seconds, type it again and hit enter again. Your phone should boot.

7. Download QuickPwn and jailbreak your phone. Restore your 2.2.1 backup in iTunes, and you should be in business.

8. For Windows: After you restore to 2.2.1, you can skip straight to running QuickPwn to get your phone up and running.

And that’s it. Enjoy an iPhone free of horrible slow-downs until summertime.