How To: Jailbreak And Update iPhone 3GS, 3G To Unlock iOS 4.2.1 On Baseband 06.15.00 With Redsn0w 0.9.6b5

This guide will show you how to use Redsn0w 0.9.6b5 to jailbreak iOS 4.2.1 on iPhone 3G/3GS and update baseband to 06.15.00 to unlock with Ultrasn0w 1.2.

Note: Make sure you have read the following information here about the latest release of Redsn0w.

The new redsn0w 0.9.6beta5 is out.  It gives both Windows and OSX users the ability to flash the iPad 06.15 baseband on iPhone3G or iPhone3GS.  It fetches the baseband files directly from Apple for now (the only IPSW you ever point it at is the stock IPSW for the FW on your iPhone right now).  There may be a long delay while it’s doing this (their servers are currently getting pounded).

  • OSX (SHA1 a322ec2c9e91993eca21abaf2e655bb44de3d7d4)
  • Windows (SHA1 7250416e17c3aea9838cdfc73712b38b025e2ed0)   (Windows 7 and Vista users, please run redsn0w as Administrator in “XP Compatiblity Mode”)

If you do flash your baseband via redsn0w, please keep it plugged into USB the whole time.  You don’t want your battery to die during the flash process!


  1. There is no way to come back down from 06.15, and there’s no hiding the baseband version from Apple. You’ll be voiding your warranty in a very obvious way.
  2. If some future baseband comes out with a critical fix, you won’t be able to update to it if it remains down in the 05.xx sequence (then again, you wouldn’t update to it if you wanted to keep your unlock anyway).
  3. Starting with FW 4.2.1 if you have 06.15 on your iPhone you won’t ever be able to restore to stock firmware (it will fail).  You’ll need to only restore to custom IPSWs (then again, if you’re unlocker you should already be doing that).

STEP 1: Download iOS 4.2.1 for iPhone 3G or 3GS (iOS/firmware links) and Redsn0w 0.9.6b5 (Mac OS X/Windows).

(Windows 7 and Vista users, please run redsn0w as Administrator in “XP Compatiblity Mode”)

STEP 2: Upgrade/Restore to iOS 4.2.1 via iTunes 10.1.

STEP 3: Launch Redsn0w 0.9.6b5 and find your way to iOS 4.2.1 and click “Open”.

STEP 4: Select “Install Cydia” and “Install iPad baseband” and then click “Next“ (read STEP 7 for how to boot tethered iDevice).

Note: A warning will prompt you. Please be aware of the risks associated with this.

Note: Make sure your device is both OFF and PLUGGED IN to the computer.

STEP 5: Follow the on-screen instructions.

STEP 6: Now sit back and relax while Redsn0w does the thing it does best, jailbreak your iPhone. After the process is complete, your iPhone will reboot and you now have a jailbroken iOS 4.2.1 with 06.15.00 baseband.

STEP 7: How to boot tethered jailbroken iPhone 3GS after reboot, select “Just boot tethered right now”.

How to Unlock iPhone 3G or 3GS on iOS 4.1/4.2.1

Follow our step by step guide below to unlock your iPhone 3G or 3GS on iOS 4.1/4.2.1 using Ultrasn0w 1.2:

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  1. So if i have an iPhone 3G (jailbroken) do I use redsn0w or iTunes to get to 4.2.1?

  2. Just like DTime… i’m a bit confused by all those updates for redsn0w and PwnageTool unlock edition and ultrasn0w….
    I have a iphone 3G with current iOS 4.0 with baseband 05.13.04. currently jailbroken with redsn0w and unlocked…

    From what I’ve read (and understood) in an earlier post, I shoudn’t need to update my baseband to the iPAD baseband… and should be able to unlock just using ultrasn0w…
    ” Then you do not need to use the PwnageTool unlock edition; you can simply launch Cydia and install UltraSn0w to unlock your iPhone. ” as said in previous How-To….

    But what about the jailbreak? which one should I use?
    Should I update to 4.2.1 with iTunes than jailbreak than unlock? and even than, which jailbreak?

    Thanks for all this :)… I really can’t wait no more to gain better performance out of my 3G… iOS 4.0 suck big balls..

  3. Jadeneastonellett says:

    Hello Damagelnc, if you have baseband 05.13.04 then you should be able to unlock your iPhone simply by downloading ultrasn0w from Cydia. The only reason you would want too upgrade to the iPad baseband is if you wanted to unlock your iPhone on iOS4.2.1. If this is the case then you will need to restore your iPhone to the iOS4.2.1 firmware, then use the pwnagetool or redsn0w to install the iPad baseband and unlock. As far as I know you cannot jailbreak on iOS4.2.1 without updating your baseband, this is why you need to use the ipads baseband. Hope this helps!

  4. Jadeneastonellett says:

    You need to first restore the iOS4.2.1 then you will need to use redsn0w or pwnage tool to apply the ipads baseband if you require an unlock!

  5. Aaahhh… thanks for the info :)
    I’ll give it a try then!


  6. I did it with my iphone 3g. i updated it in itunes to 4.2 (4.2.1) then i ran redsn0w.( make sure you have the right “.ipsw” downloaded. ++ At first i had the itouch one download so it was giving me trouble.++

  7. does this support iPhone 4 yet?

  8. This worked like magic!! Thanks for the simple and clear explanation.

  9. jay shah says:

    i have 6.15 baseband and ios 4.1.. so how can i upgrade to 4.2.1 ??

  10. kontol meki

  11. the link is broken… where can i find this?

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