August 9, 2022
UltraSn0w Unlock Gets Updated to Support iOS 4.3.1

UltraSn0w Unlock Gets Updated to Support iOS 4.3.1

Posted April 10, 2011 at 12:57am by iClarified · 78146 views
The iPhone Dev-Team has announced an update to UltraSn0w that makes it compatible with iOS 4.3.1 for basebands previously unlocked.

We’ve pushed out the 4.3.1 compatibility fix for ultrasn0w in Cydia — it’s now at version 1.2.1. If you’re not already at 4.3.1 and you need the unlock, please be sure you understand how to get to 4.3.1 using a custom IPSW that doesn’t update your baseband. There are lots of guides for this (like at

This isn’t a new unlock! It’s to allow those who are already unlocked to use FW 4.3.1. It also fixes the signal bar issue for those who aren’t using the unlock but retain an older baseband intentionally.

After installing UltraSn0w 1.2.1 you should reboot your device by using the normal power button and "Slide to Power Off" swipe. USA T-Mobile users need to disable 3G mode in Settings:General:Network.

To upgrade to iOS 4.3.1 without upgrading your baseband you can use one of these tutorials
● TinyUmbrella iPhone 4 (Windows, Mac)
● PwnageTool iPhone 4 (Mac)
● PwnageTool iPhone 3GS (Mac)

You can find our UltraSn0w unlock tutorial here.

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UltraSn0w Unlock Gets Updated to Support iOS 4.3.1
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Alan - June 14, 2011 at 2:32pm
I have a iPhone 3G (originally on Orange France) and wondered if I could unlock it. Jailbreaking is no problem but unlocking with UntraSn0w doesn't seem to work: iOS version - 4.2.1 Baseband - 05.15.04 There don't seem to be any references to this baseband anyone got any ideas? Regards A
George Belivanis
George Belivanis - April 14, 2011 at 9:24am
hey guys, im in serious need of help. i upgraded my iphone 3gs to ios 4.3.1 and the jailbroke it using a tutorial on the iclarified website. everything was running smoothly until i went to unlock it from the current provider but it wouldnt let me because it had baseband 5.16.2 i am absolutely lost and ive been reading up on blogs which say that now its useless and i cat do anythin with it...
hellinwtc - April 15, 2011 at 12:20pm
if you upgrade 4.3.1 using the official ipsw then you baseband will be upgrade as well so until this point you can't unlock using ultrasn0w coz it does not support new baseband
francios - April 29, 2011 at 4:45am
is there any alternative? beside ultra snow? please i really need to unlock it...
LOCO - May 22, 2011 at 3:25pm
I got the same problem. Modem Firmware 5.16.2 and can't downgrade. What about the Gevey Turbo whatever? Could they be the solution?
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