Dennis Koh's Blog

This jailbreak has been proven to work on iPhone 3GS, iPhone 4 and iPad. I used GreenPois0n for this jailbreak. Make sure you have iTunes 10.1.2. The firmware version on your iPhone should be 4.2.1 (8C148a)

Step by step to jailbreak.

1. Download GreenPois0n. Click here to download GreenPois0n.
2. Connect your iPhone to your computer. (Close iTunes if it pops up.)
3. Switch off your iPhone.
4. Double click on GreenPois0n. (Click on no if it asked if you are jailbreaking Apple TV.)
5. Click on jailbreak.

 



 

6. Wait for the timer and then press and hold on the sleep button (which is also your power button).
7. Follow the timer and then press and hold on the Home button while still holding on to the sleep button.

 



 

8. Follow the timer and then release the sleep button while still holding on to the  Home button.
9. You may see that GreenPois0n says complete on the jailbreak window.
10. Keep holding the Home button. It will take a while. So be patient. You will see the screen turns black with 3 lines of text and then hang there for a while. And then followed by a whole page of text running through. Do not panic. Keep holding on to the Home button.
11. Until you see the iPhone restart. You will see the Green Pois0n logo.
12. You can now let go of the home button.
13. Start your iTunes if it does not start. (This step is important. If you miss this, it will put you back to DFU mode or show failed on the jailbreak program.)
14. If you managed to go through the restart step, you will see a green icon called Loader when the iPhone starts up. Click on it to install Cydia. (You must be connected to wifi to do this.) Your iPhone is now jailbreaked. Enjoy!

If the jailbreak fails, just connect the iPhone to your PC and switch it off and repeat the above step.

 

Feel free to comment if there is any questions.