iPhone Help with JB/Unlock 3G 4.2.1 05.15.04

[leftkidney]

so about 1 or 2 times a year I am call upon to JB someones iphone since I am the only one of my friends who is smart enough to do something like that - I know that sounds stupid since I am asking this question but I dont do this every day so I am not up on the latest stuff and without trying to sound like a total dick I dont really have time to research everything I need so I would rely on the forums with really helpful users that dont mind helping someone with a simple question

I have a 3G 4.2.1 (8C148) - 05.14.04

can I just update using itunes to the latest that it will update for the 3g iphone, or is that the latest?

do I have to do something with the ipad baseband, I remember that from before but I assume something has changed since then

I want to Jailbreak install Cydia and Unlock the phone for use on tmobile or another gsm carrier


thanks for the help

 

[45357254]

Latest firmware for 3G is 4.2.1 (which probably can't run any app store application)

ipad baseband isn't necessary anymore as long as you have the needed baseband of ultrasn0w.
(4 -> 01.59.00)
(3G/3GS -> 04.26.08, 05.11.07, 05.12.01, 05.13.04 and 06.15.00!)

after jailbreaking , go into cydia and install ultrasn0w 1.2.8, and you are done.

 

[PsstGreek]

Ultrasn0w can't unlock your baseband. You can purchase an IMEI (factory) unlock from Swift Unlocks for $1.99.

Then you can jailbreak with redsn0w