Main Content iPhone & iTouch Jailbreak / Unlock Matrix (visit JailbreakMatrix official web site for more info.)

To jailbreak a iPhone 3GS on 3.1.3 you NEED to have your iPhone previously jailbroken and uploaded your SHSH to cydia, otherwise you wont be able to downgrade firmware and jailbreak, that is the only way. So if you want to restore to 3.1.2 you’ve had to backed up your SHSH on 3.1.2, get it ? But if you are not on 3.1.3 yet you can upgrade to 3.1.3 using custom jailbroken firmware, see guide below.

To jailbreak and unlock a iPhone 3G on 3.1.3 you NEED the old bootrom or you can’t downgrade your baseband using fuzzyband and unlock it, but there is no problems jailbreaking it, see guide below.

Disclaimer : These guides are only for information purposes. You should follow these steps at your own risk. Jailbreaking voids your warranty but it can ALWAYS be easily fixed by restoring the iPhone OS via iTunes. Before jailbreaking READ the whole guide, updating to some firmware may cause you to lose your unlock permanently, meaning you won’t be able to use other carriers until the DEV Team releases a new unlock.