Jailbreaking the iPhone 3GS revisited

When we last visited this subject I updated my used 3GS to iOS4.2, jailbroke and unlocked the phone.

Well now about a year later, I am doing it again...why? To take advantage of a couple of new features...and allow some apps to work/better.

Since it had been so long, and there had been numerous iOS updates since then (5.0.1 is the latest) I had to research the subject all over again, and re-learn the terminology.

Key words: iOS version, untethered, unlocked, radio or baseband or 'modem firmware', Hacktivate.

Once you have definitions for those, then you can decide how to proceed.

(in no particular order) I knew I wanted to unlock the phone, the 3GS was an AT&T phone, but I use my own sim, and only use the phone part outside the US...so I need the phone unlocked to use a phone service other than the one who sold the phone.

I had previously unlocked it, so the 'Modem Firmware' (Settings-General-About) is 05.13.04, a known unlockable version.

I don't want to have to hook it up to a computer every time it restarts...since I rarely travel with a computer anymore...so the Jailbreak needs to be Untethered.

With that info I can start deciding what iOS I can use.

Well the answer is 4.3.3 (for now)...nice link here. (list at top of page)

The newer iOS Jailbreak are all tethered. (for now)...so I can't go any higher.

So know I know that I will be doing a iOS 4.3.3 untethered Jailbreak with an Unlock, (and a computer running windows) that forces me to use Sn0wbreeze (that is a zero in place of the 'O').

Sn0wbreeze edits the iOS restore file for the OS you will be using to not allow iTunes to mess up your device. In my case it will stop iTunes from upgrading my 'modem firmware', so I can later unlock it.

Here is the guide I followed, the link for Sn0wbreeze changes with updates, but go to ih8sn0w.com for links to recent version. (2.7.3 right now.)

If the descriptions are confusing, here is a different guide, (same iOS but different phone) with pictures that should help...I don't know if the text is the same, but the pictures are what I saw.

Now before I did anything, I did a 'transfer purchases' and 'backup'. (and made sure the phone had a decent charge)

I won't go through all the steps of Sn0wbreeze, but I will explain two of them.

First, I want to maintain the "Baseband' (modem firmware) so in the Expert mode of Sn0wbreeze I make sure the upgrade to 6.15 option is UNCHECKED.

Second, I don't have an active AT&T sim card (I have the card that came with the phone, but not with me right now), so I will need to Hacktivate the phone. That means iTunes will assume the phone has been properly registered with AT&T, and therefore will continue installing apps and things.

The whole process took almost half an hour from Sn0wbreeze editing the file, to iTunes installing it on the phone. Then probably another half hour to restore all my data and apps from backup.

The last step, after everything is restored and iTunes is done syncing, is to launch the Cydia app (Sn0wbreeze installs that too) and install Ultrasn0w.

Guide here...Ultrasn0w is what unlocks the phone to allow you to use whatever carrier's SIM card you want. I didn't have to do any editing (like the instructions show) I just searched for Ultrasn0w, installed it, and launched the app. After a few minutes the phone rebooted, and I was successfully on the T-Mobile network.

There are so many options, that it is hard to figure out what applies...but the most important thing is to not upgrade the Baseband (Modem Firmware) until you figure out if the one on the phone is an unlockable version. (hint, nothing above 5.13.04 is unlockable until 6.15.00, and that version has questionable results with the 3GS GPS) If your version is not unlockable, and you are above 5.13.04, then you have to upgrade to 6.15 to be unlockable...

Good luck!