The Iphone jailbreaking/unlocking thread

This will be the thread I wish had existed when I first got my used Iphone 3gs a couple of weeks ago.

Thinking about jailbreaking your Iphone or unlocking it to escape the dreaded AT&T? I’m a n00b at this stuff myself, but I will share my very recent and ongoing experiences.

Whether and how you jailbreak and unlock depends a lot on which phone you have, your firmware and your baseband (modem firmware) versions, which you can find out by going to Settings | General | About. has some pretty good forums, but asking questions there is likely to yield you only new questions, because no one there explains things very well. has some good tutorials.

There are other people here who know all about this stuff as well, probably way better than I do. So ask away…

I’ve heard that the sim on the 4.0 is actually shaped differently than other sims.

I’m going to be in NZ for over a month, so jailbreaking it makes some sense, but with all the issues inherent in getting it to work, I’m close to just using it as a touch, and renting another phone while I’m there.

Yeah, I think you have to trim the standard SIM down to make it fit in the 4. I believe there are SIM cutters sold on Ebay for just that purpose. I wonder if Apple is just trying to make it harder to use their phone on other networks.

MicroSIMs are used by other devices, I think. I bought a SIM cutter but most providers let you transfer your service through web-based logins to another SIM, not caring if it’s a MicroSIM or not.

Wow. They have this down to a science. Apparently my wife’s iPhone 3GS hadn’t been updated in awhile which made it very easy. I went to a website, let it do its thing, then launched the snow thingo from Cydia and now it is unlocked and works with other sim cards.

Now that that is done, what will happen if we plug it into iTunes? Can we still sync apps/music and whatnot but just not update the actual OS?


I’ve got an iPhone 3GS that doesn’t want to unlock (4.0.2 with baseband 5.13.04). Ultrasn0w seems to work, but the Wind sim I’m using just shows “no service” (works in my Nexus S though). I’ve found a bunch of reports of similar results, but no solution that works on this device so far.

I wonder if I’d have better luck updating it to a newer release and trying again…

I have a 3GS running 3.1.2, jailbroken and unlocked. If I want to upgrade it to the latest/greatest, do I just upgrade it in iTunes first, then jailbreak+unlock? Or do I need to do something else first?

Save your shsh blob with tinyumbrella. Whatever that means.

That sentence needed 0.5 days of research to figure out.

In the end, I left the phone alone. The key thing I figured out is that to unlock it after upgraded to iOS 4.2.1, I need to upgrade the baseband firmware to an iPad one, and this operation cannot be reverted…only upgraded in the future.

Never upgrade using itunes if you want to preserve your unlock-ability.

If you’re on baseband 5.13 or lower (in settings>general>about) you can update to 4.2.1 using pwnagetool on a mac, and preserve your unlockable baseband.

Basically, you use pwnagetool to create a custom version of the .ipsw (the iOS install file) with an intact baseband.

You can then update your phone through itunes (using the shift-restore option that allows you to specify a firmware file - point it at the one you made using pwnagetool). This’ll get you to iOS 4.2.1 with your previous unlockable baseband.

I personally wouldn’t bother futzing with the ipad baseband kludge; as you say, you’re then locked in to it, and there are reported issues with the GPS receiver after updating to it.

Oh, and the only reason I know this much detail about jailbreaking/unlocking is because I imported a US iphone 3G that was super laggy on 4.0 and hence needed to be updated; I live in New Zealand!

The best part about that baseband kludge: if you do it, you cannot restart the phone (!) without plugging it in to USB and re-running redsn0w. Ouch. The documentation makes it sound like you can’t run jailbreak apps unless you start that way, but no – the phone literally will not boot without tethering and re-running redsn0w. There’s a hack around that for the iPhone 4, but not the 3GS, and not if you intend to unlock.

Yeah, so now, don’t. I am staying on 4.1 with my iPhone 4.

Actually, I think it’s the firmware and not the baseband that locks you into that tethered reboot. I have a 3GS with the Ipad baseband and was running tethered until I got tired of it and downgraded the firmware. I’m now running 4.1 and baseband 6.15.00 with no issues.

What did you need to do to downgrade the firmware?

in case people don’t know, baseband 6.15.00 is the ipad baseband. Latest current iphone baseband is 5.15.04.

I don’t have a Mac, so no pwnagetool.

…but since I’m keeping the unlocked one to 3.1.2…I can make it untethered! Thanks for letting know this is possible, jerri! Is it with limera1n?

limera1n is braindead easy. just run the exe and follow the instructions.

Did you upgrade to 4.2 from 4.1 yourself? If so, does your phone have Cydia on it? If so, open it and look at the top of the home page to see whether it says SHSH: iOS 4.1, which means your 4.1 BLOBs are backed up.

If all the above is true, go here for a good tutorial on downgrading.

Honestly, I did so much crap to this phone over the course of a weekend that I don’t remember how I unlocked it the last time, but yeah, I think I used limera1n to jailbreak it and ultrasn0w to unlock it.

upgraded itunes to; downloaded and ran limera1n. Now my phone keeps showing the “plug into itunes” screen after limera1n turned it off.

wikipedia says that limera1n doesn’t work on 3.1.2 (works with 3.2.2 and up); and blackra1n has stopped working now, too. I think I just bricked my phone…so should I just restore to 4.2.1? I know I cannot restore to 3.1.2 anymore…how about 4.1?