Apple has released firmware 3.1.3, with the release of new firmware, jailbreaking and unlocking tools are emerging as well. Earlier, we shared the procedure to jailbreak iPhone 2G, 3G and 3GS (Older Bootroms Only) with sn0wbreeze on latest iPhone firmware 3.1.3. Snowbreeze actually preserves your older baseband while upgrading your device to the latest iPhone 3.1.3 OS/firmware. We have already shared a tutorial on unlocking your iPhone on 04.26.08 baseband using ultrasn0w. If your iPhone is on 05.11.07 baseband, than this tutorial will help you to unlock your iPhone via blacksn0w.

This post is about Unlocking iPhone 3G and iPhone 3GS (Old Bootroms only) on firmware 3.1.3 via Blacksn0w. iPhone 2G users can unlock and jailbreak their iPhone using redsn0w, details are posted here.

Steps To Unlock iPhone 3.1.3 Firmware Via Blacksnow

1. First you will need to jailbreak your iPhone 3G/3GS on firmware 3.1.3, step-wise procedure is posted here
2. To unlock your jailbroken iPhone using blacksn0w, follow these steps:
• Start "Cydia" on your iPhone.
• Touch on "Manage" tab on the bottom.
• Now touch on "Sources" as seen in the screenshot below:



• Touch on "Edit" and then on "Add". You will be prompted to enter a url source as seen in the screenshot below. Type "http://blackra1n.com" and touch on "Add Source"



• Cydia will now automatically update your sources by following a series of automated steps.
• After installation is completed. Search for "blacksn0w" in Cydia and install this application. This application will then automatically unlock your iPhone so that you can use it with any carrier.



3. That's all. Just give a hard reboot to your phone in the end and you should have fully jailbroked and unlocked iPhone 3G/3GS on firmware 3.1.3.

NOTE: Please try this at your own risk, we haven't tried this procedure ourselves. You might want to wait for official tools to be released by Dev-Team and Geo-Hotz for firmware 3.1.3.

UPDATE: If you are facing issues in unlocking, please refer here for FIX available for Blacksn0w.

Please visit here and here respectively for complete coverage on jailbreaking and unlocking iPhone 3.1.3 firmware.