1. Supra1jz's Avatar
    Hello all i have a 3GS on 4.0.1 with baseband 5.13. And I would like to upgrade to 4.2.1 and I would like to know how to make a custom firmware so I can stay on the baseband 5.13 cause I am unlock and would like to be unlock cause I use t-mobile. What is the right way to do this i am on windows 7 is they a video or somthing that can show me how to do this thanks all.
    12-13-2010 07:21 AM
  2. myzhi's Avatar
    1) Create (pwnagetool) or find (google) custom 4.2.1 firmware file (one that keeps your current baseband).
    2) You must use Pwangetool or Redsnow and put the phone into a special DFU mode.
    3) Through iTunes, restore from the custom firmware file from step #1.
    4) On the phone, with Cydia, install Ultrasnow to unlock.

    **Note: JB is untethered for old bootrom 3GS and tethered for new bootrom. Google if you want to find out which one you have.
    Supra1jz likes this.
    12-13-2010 12:11 PM
  3. Supra1jz's Avatar
    Ok thanks for you help and sorry it took me so long to repost I am running windows so I have to use redsnow right and I know how to put it in DFU mode what I have never done is a custom firmware so I am sorry for all the newbie questions and boot rom what is that is that my baseband if it is I am 5.13.04 but I will google to see what is old and new boot rom I was trying to get my brother to make me a custom firmware with his Mac but like always he is busy so I will just have to find the way to do it myself. As soon as I het home to my computer I will google all the info thanks
    12-13-2010 05:34 PM
  4. myzhi's Avatar
    Bootrom is different from baseband and not related. With early release 3GS(old), there was an exploit that allow people to JB the phone. Apple fix the exploit in the later 3GS(New). With that exploit and recent one from 4.1, Dev Team was able to make a untethered JB for 4.2.1. Thus, w/o that exploit, the new 3GS can only be tethered JB 4.2.1 using the only recent found exploit used in 4.1.
    Last edited by myzhi; 12-13-2010 at 05:44 PM.
    Supra1jz likes this.
    12-13-2010 05:42 PM
  5. Supra1jz's Avatar
    Ok i google how to check if I have old or new boot rom now when I put it in dfu mode after I'm done I can use tinyumbella to kick it of of dfu right?
    12-13-2010 05:51 PM
  6. myzhi's Avatar
    Ok i google how to check if I have old or new boot rom now when I put it in dfu mode after I'm done I can use tinyumbella to kick it of of dfu right?
    Believe, you can just hold power & home button to turn off the phone. Then, hold the power button to boot up like normal.
    12-13-2010 06:23 PM
  7. Supra1jz's Avatar
    ok thanks i am home not and i am going to try all these steps thanks for all the help guys..
    12-13-2010 06:36 PM
  8. Supra1jz's Avatar
    ok i put my phone in DFU mode and i have checked i am on the old boot rom 359.3 so it is ok for me to upgrade to 4.2.1 cause i will be untethered correct?
    12-13-2010 06:58 PM
  9. myzhi's Avatar
    ok i put my phone in DFU mode and i have checked i am on the old boot rom 359.3 so it is ok for me to upgrade to 4.2.1 cause i will be untethered correct?
    That would be YES.
    12-13-2010 07:02 PM
  10. Supra1jz's Avatar
    ok now i have to get the new redsnow correct and download the latest firmware 4.2.1 and open it with redsnow and after that save it to my desktop and from there upgrade with itunes with (Shift) restore with the firmware redsnow will make me right..

    just so i get it right i can download 4.2.1 from here
    iPod, iPhone and iPad Firmware Download

    and redsnow from here
    Dev-Team Blog
    12-13-2010 07:07 PM
  11. myzhi's Avatar
    ok now i have to get the new redsnow correct and download the latest firmware 4.2.1 and open it with redsnow and after that save it to my desktop and from there upgrade with itunes with (Shift) restore with the firmware redsnow will make me right..

    just so i get it right i can download 4.2.1 from here
    iPod, iPhone and iPad Firmware Download

    and redsnow from here
    Dev-Team Blog
    I posted the instructions above.
    Step 1) You need a custom 4.2.1 firmware. DO NOT use an official firmware file otherwise it will also update the baseband.

    Follow the rest of the steps.
    12-13-2010 07:11 PM
  12. Supra1jz's Avatar
    ok do i just google it or there is a place were i can find this ?
    12-13-2010 07:13 PM
  13. Supra1jz's Avatar
    12-13-2010 07:14 PM
  14. Supra1jz's Avatar
    i would like to give a very big thanks to (myzhi) for all your help and support as of right now i am on 4.2.1 with my baseband at 5.13.04 thanks you very much for all your help..

    P.S sorry for all the newbie questions i just wanted to get it right this will help out other and now i can also help other with this i have save all the link thanks again..
    12-13-2010 07:50 PM
  15. myzhi's Avatar
    Congrats and your welcome.
    Supra1jz and farbod21 like this.
    12-13-2010 08:05 PM
  16. Supra1jz's Avatar
    ok i now have everything working on the phone (MMS) internet sofar picture coming in good send and receiving now all i have to do is put all my apps back on the phone thanks again..
    12-13-2010 09:08 PM
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