To upgrade to i OS4 on your i Phone 3GS, i Phone 3G and i Pod Touch, you will first of all have to upgrade i Tunes 9.2, you can download or upgrade i Tunes 9.2 using the Apple Update manager.
Once you have updated your i Tunes, connect your device, accept the terms and visit the summary page for the device.
Once you have this firmware, move it to a place that you can find it, such as My Documents.
Now, plug in your i Phone to the computer hold Shift and click Restore.
Try put your device into DFU mode (device firmware upgrade mode). Hold the power button past the slide to unlock page (around 12 seconds) and as soon as your i Phone turns off, hold the home button for another 15 seconds until you hear a "Du-du" on your computer.
Then, try to shift restore using that firmware that you downloaded. I was able to jailbreak but no luck with unlocking. Received message in Blackra1n that iphone unlocked. When I reboot I see only iphone logo and does not move further. Jailbreak your i Phone again (you may have to downgrade). Once you have downloaded Fuzzy Band, it will check your i Phone's bootloader version.
But my phone crashed last week and I end up updating to os 3.1.3. I tried downgrading to OS 3.1.2 (using itunes method, redmond..), but phone crashed in unlocking or booting. I searched everyplace for unlock for OS 3.1.3 and my new bootram (MB048LL), but could not find any.
In this guide you’ll learn how to unlock i Phone 3G baseband.You can now jailbreak and unlock your i Phone because you are on 3.1.2 firmware! If you need a full guide with pictures, you can visit this forum thread.You can ignore the part about the hosts file because you are not on a 3rd Generation device. t=277386 Well, what is the worst that could happen? If you have a 3G i Phone (not the 3GS) the downgrade will work 100% of the time, as long as you get the correct firmware download.i OS4 will be out shortly, in-fact it is only a matter of few hours away.If you haven’t yet read about i OS4, it is a rechristened name for the i Phone OS 4, which has a lot of new features, including Multi-tasking, folders for apps, unified inbox, wallpaper support and more.i OS4 though also is a bit of a battery drain and can make you run for the charger faster than i Phone OS 3.1.3, however, with the slew of new features it is definitely a exciting upgrade. Read ahead.i OS4 will be released to the general public on June 21, this is different from the i OS4 GM release which was released for developers.If you have an i Phone 3G on i OS, you can jailbreak by following these instructions.Every time a new i Phone OS comes out, it gives headaches to jailbreakers and unlockers. The new i Phone OS 3.1 has been available for a few weeks and the Dev Team has successfully been able to unlock it.It took a while but all 3 i Phones (i Phone 2G, 3G, and 3GS) can now be unlocked.You will either need to use Pwnage Tool or Ultra Sn0w to unlock your i Phone, depending on the model.To jailbreak and unlock again, you just simply need to downgrade your i Phone to 3.1.2.To do this, you can find a download link for the 3.1.2 firmware (google Felixbruns i Pod for a good website).