Jailbreaking and unlocking a 3GS

[Fredini]

Hi Everyone,
I am trying to jailbreak a 3GS for my teeenage daughter, then unlock it to work on tmobile. I want an untethered solution.
- OS is currently iOS 5
- The Bootrom is iBoot-359.3, which is good because it is the old one!
- Modem Firmware is 05.16.05
- I am using OSX, not windows


So, my questions are:
1) Should I revert the phone to iOS4.something or jailbreak it under ios 5? If I revert do i revert to 4.1, 4.35, or something in between?


2) Sounds like I have no choice but to do the baseband update to ipad baseband (6.15)- is this correct?


3) Will I do all this with the old AT&T simcard in it or no sim card in it? or doesn't it matter?
I wait to put the tmobile simcard in until after I unlock, right?


From all that I am reading, it sounds like I want to run Redsn0w on top of iOS 5 and install the ipad Baseband. Then I will run Ultrasn0w to unlock it. It sounds like this may break GPS on the device, but we can live with that. I just want to know all the issues first so I don't end up bricking this thing! There's a ton of info out there but so much of it seems out of date. Does this sound like the right approach?

Thanks for the advice!

 

[Fredini]

Nevermind, I ended up successfully unlocking the phone- see here if anyone cares.

Moderation Notice: This post has been edited by a member of staff in accordance with the Forum Rules

 

[Isak]

Hi.. Can you let me know the steps used for unlocking?!
I am stuck up with the same problem..

 

[ashfaqimran]

Hi,

I have the same situation except i dont know the bootrom and i use windows. Can you help me find any tutorial which helped you unlock?

Thanks

 

[cowen1000]

What firmware are you using? What baseband?

If you are using a baseband higher than 5.13 then you will have to update it to ipad 6.15 using redsn0w. If you want an untethered jailbreak then you are going do have to be on 4.3.3 or earlier. 4.1 is still signed so you can downgrade to that without any problems.

Once jailbroken and correct baseband is installed then you just use cydia and download ultrasnow to unlock

 

[ashfaqimran]

Thanks Cowen1000,

Here is my situation.

1) 3gs 16 gb, bb 6.15.00, BL 6.4, S/N xx005xxxxx, JB custom 4.3.3 using snowbreeze and unlocked through ultrasnow however i get searching/no signal. what shall i do to fix it.

2) 3gs 16 gb, bb 5.16.05, BL 6.4, S/N xx939xxxxx, JB custom 4.3.3 using snowbreeze and unlocked through ultrasnow however i get searching/no signal. what shall i do to fix it.

I just need a untethered jailbreak and unlock so i can use on T-Mobile.

Thanks