Sunday, November 28, 2010

iPhone 3GS/3G Unlock Guide for iOS 4.1 4.2.1

WARNING: unlocking your iphone 3GS / 3G will void your apple manufacture warranty

This step-by-step guide is to aid you through unlocking your iPhone 3GS/3G that are current on iOS 4.1 or iOS 4.2.1. If you are not on the firmware version. You may simply restore your iPhone to the specific OS version. If there is anything unclear in the process, feel free to comment and i will try my best to explain. The whole process may take about 30 minutes if you do it for the first time. It should take only 10-15 minutes if you are proficient.
  1. Download your iPhone firmware from here to desktop.

  2. Download redsn0w 0.9.6b6 Windows or Mac to desktop.

  3. Connect iPhone to computer via USB cable. Run redsn0w and choose the firmware you have just downloaded and Click next.

  4. If you are running 3GS, follow the instruction to identify whether your iphone 3gs is a newer model or older model by looking at the serial number

  5. Check install cydia and install iPad baseband (confirm yes).

  6. Click next and turn off your iPhone

  7. follow the on screen instruction to boot your iphone in DFU mode.

  8. Once it is indicating it's fetch iPad baseband files, you may release all buttons and let it ride on its own. Please do not unplug the cable during the process. it will take approximately 5-10 minutes or so to finish.

  9. Once redsn0w inidicates that it's done. close redsn0w but keep iPhone connected to the computer to make sure it does not run out of battery while it is running.

  10. Make sure you have a WIFI or 3G connection so you can connect to internet from now on. You can configure the wifi settings to connect to a nearby wifi hotspot.

  11. After the process is completed on the iPhone. Start the Cydia app on the iPhone.

  12. In Cydia, choose user/done.

  13. In Cydia, choose Upgrade Essential and then reboot device if a dialoge box pops up.

  14. In Cydia, click on Manage tab, choose sources->>ultrasn0w and click install/confirm.

  15. Reboot the device, pop in your sim card and you are ready to go

Known issues:

  • iPhone 3G / 3GS baseband will be upgraded to a different version that what the official firmware has. You will run into an error when you try to restore to 4.1/4.2.1 official firmware in the future. Just simply run umbrella and choose kick out of restore mode after the restore.
  • Sometimes umbrella's kick out of restore mode does not work for iPhone 3G when you restore to firmware 4.2.1. Simply restore to firmware 4.1 and choose kick out of restore mode and it should work 100%.

  • iPhone 3GS post-41 week on iOS 4.2.1 will have untethered jailbreak. You will have to connect to computer to re-jailbreak it if the iPhone runs out of battery or powered off.


  1. It is a good methods and information about the unlocking iphone mobile.....
    In this way i like to share my experience in unlocking mobile.....i am using iphone 3g mobile its unlocked through this site , here it gives the easy instructions to get the mobile unlocked through remote unlocking method.........

  2. Tried this iphone factory unlock process but this did not work for me. So I decided to get an iphone factory unlock service to have my phone unlock. And I'm really glad my phone was unlock permanently in just 24 hours.