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09-15-2012, 05:32 PM #1How can I downgrade/jailbreak/unlock my iPhone 3G?
I have a:
jailbroken and unlocked
firmware 4.0.2 (8a400)
I would like to know how to:
downgrade to firmware 3.1.2
jailbreak and unlock it to use on T-Mobile USA
Last edited by itzzjason; 09-16-2012 at 10:12 AM. Reason: left out something
09-15-2012, 07:02 PM #2
Your phone is already unlockable with that baseband, so that's good. If you want to downgrade, I would suggest 3.1.3. It's optimized better than 3.1.2, but essentially the two are almost the same. Simply download a stock 3.1.3 ipsw (you can find it here in the Downloads section on MMi). When you've got everything backed up and ready to downgrade, open up iTunes and hold shift (option on mac) and click restore. It will prompt you to select your ipsw, so navigate to your 3.1.3 ipsw and select it.
It will downgrade, if you happen to run into error 1015, simply download TinyUmbrella and use the "exit recovery" option (not the fix recovery option). It will kick the device out of recovery and boot up.
All you have to do then is to download Redsn0w 0.9.4 to jailbreak. If you have an official SIM card to activate with (the SIM for the carrier your phone is locked to) do so before jailbreaking. Spirit JB is way faster and easier to use than RS for 3.1.3, but it can only be used if you have an official SIM to activate with. If you don't, then use Redsn0w.
JB with Redsn0w is simple, just launch it and follow the on-screen instructions.
After you finished JB, open up Cydia on your springboard. Let it organize, it'll exit out after. Open it again, and let it process. Then go to the changes tab below, then hit "refresh" and it will likely have a few updates for you. Choose to do a complete upgrade. After, your phone will likely need to reboot. After reboot, go back into Cydia and search for "Ultrasn0w" and install it. Reboot your phone after installation twice. You should then be unlocked. Put your T-Mo SIM in. It can take 15-30 minutes to find service. It could be less, in my experiences it usually took around 15 minutes for me to pick up service.
For SMS and Internet, I'm sure there's a thread around here that gives you the appropriate APN settings. You can set it all up to work on T-Mo. Be sure you have Wifi when you're doing all of this or you won't have connection to install anything from Cydia.
09-16-2012, 01:12 AM #3
09-16-2012, 07:54 AM #4
No it doesn't matter. The process is still the same.
09-16-2012, 09:36 PM #5
is this where i download tinyumbrella? The Firmware Umbrella - TinyUmbrella
how come i can't use the latest version of redsn0w?
Download (Direct links), Jailbreak Guides, And Mac OS X - Redsn0w, Redsnow Jailbreak 5.1 untethered / Jailbreak iOS 5 / 5.0.1 / 4.3.5 iPhone 4S, iPad 3
is this the correct site to download redsn0w?
the earliest version it offers is 0.9.6rc13 for windows
09-16-2012, 10:57 PM #6
Yes to the TinyUmbrella question.
No you can't use the newest redsn0w it doesn't support 3.1.3.
If you're having trouble finding 0.9.4 version of Redsn0w you may consider learning how to create a custom 3.1.3 ipsw with Sn0wbreeze from ih8sn0w.com.
It will downgrade and jb the phone simultaneously. You will not need to use TinyUmbrella if you use Sn0wnreeze.
09-16-2012, 11:27 PM #7
09-17-2012, 08:49 AM #8
ok so i held shift and clicked restore on itunes. it attempted to restore the iphone 3g to 3.1.3 (i downloaded the ipsw from iphonefirmware.com)
it gave me the 1015 error and said it couldn't restore
i opened tinyumbrella and clicked exit recovery
now the phone appears to be stock 3.1.3
i downloaded redsn0w 0.9.4 here on MMi downloads section. opened it up
redsn0w first asks to select the ipsw that my phone is currently on
i selected it but it says it doesn't recognize the firmware. so now i can't continue with the jb/unlock
09-17-2012, 08:50 AM #9
09-17-2012, 09:15 AM #10
09-17-2012, 09:17 AM #11
09-17-2012, 09:57 AM #12
did something go wrong?
i opened redsn0w and pointed to a 3.1.2 firmware (downloaded from iphonefirmware.com)
followed the on screen instructions
the jb progress bar is stuck at approximately 90% and is at the "uploading ramdisk" step. hasn't changed for awhile
09-17-2012, 10:00 AM #13