Can not jailbreak my iphone 3g

[rusty11]

Can anyone please please help I have had several people attempt to jailbreak my phone and all have failed I have attempted it myself on redsn0w, greenpois0n etc etc and have also failed it runs on version 4.2.1 and I would like to keep it on this if possible firmware is 05.1504, my phone is already unlocked so all I would like is for it to be jailbroke???

 

[willerz2]

You'd need to preserve your baseband and jailbreak using the baseband preserved IPSW. This requires pwned DFU-ing your 3G. There's no jailbreak for the 4.2.1 that retains the unlock nor the data on your iPhone because it does require a fresh restore of iOS onto your device. 4.0.1 is the last iOS that's supported by JailbreakMe, which does not use an IPSW to jailbreak because it uses a PDF exploit.

 

[rusty11]

hi, any chance of talking me through what exactly to do??? thanks

 

[willerz2]

Back up everything. Put your device into DFU using this sticky's instructions.

http://www.iphoneforums.net/forum/iphone-jailbreaking-17/dfu-mode-dummies-16020/

Go into iTunes and hold Shift and click Restore and point it to the 4.2.1 IPSW to give your iPhone a fresh install. After it's finished, open up RedSn0w. Select jailbreak. Follow the on-screen instructions to put your device into DFU mode again (or just put it into DFU after you've installed a clean copy of 4.2.1 on your 3G). Check Install Cydia. Wait for the magic of RedSn0w to work.

 

[rusty11]

hi, thanks, is there any version of redsn0w I should use in particular? If there is anything that I dont quite get is it ok to contact you for advice? thanks