downgrading iphone 3g on 4.0 to previous unlock-able firware

[mr_motta1989]

i want to downgrade my iphone 3g from 4.0 to the previous firmware that can be unlocked and jailbroken. i have it on tmobile. can someone point me in the right direction? which firmware would i downgrade to? can i downgrade? thanks in advance for everyones help

[munkE]

Do you have 4.0.2 or 4.0.1? Because 4.0.1 is jailbreak-able.

[mr_motta1989]

4.0.1 jailbroken and unlocked but i want to go down because it sucks and ive been putting up with it way to long. it freezes certain apps wont run properly and its annoying so i finally just want to go back if i can.

[munkE]

Caching Apple's Signature Server - Jay Freeman (saurik)

That will help if you have SHSH blobs on Saurik's server.

Another option would be to just update to the latest 4.2.1 firmware and jailbreak that. Tutorials for this are all over you tube.

[mr_motta1989]

but which is the previous firware i can go to that i can jailbreak and unlock so i can use it under tmobile

[munkE]

3.1.3

[mr_motta1989]

ok thanks

[munkE]

Anytime

[i.Annie]

You still can't unlock even if you downgrade. The firmware version isn't what determines the unlockability, it's the baseband (modem firmware). If it is 5.13.04 and below, its unlockable. If not, you'll have to go to 4.1 or 4.2.1 and upgrade the baseband to 6.15.00 to unlock. This can cause a loss of GPS function, which is unknown who might get that problem or who might not. Its a gamble really.

[mr_motta1989]

it is at baseband 5.13.04 i have it currently unlocked i just dont know if it will still be unlockable afer i downgrade. can you give me a simple way to downgrade. do i have to download the 3.1.2 or 3.1.3 firware from the felix burns webstite? then after that restore my iphone through itunes to that firmware? then i think use spirit to jailbreak? then.......

[i.Annie]

Then downgrading won't affect your unlockability.

Just shift+restore to stock 3.1.3 and jb as normal. If you restore and get error 1015 just exit recovery mode with TinyUmbrella

[mr_motta1989]

do i get the stock firmware from the felixburn website? will i lose everything i have never synced this iphone to my mac or pc and i think itll delete everything if i do. is there a way to back up through cydia?

[i.Annie]

You can do either that or get it from ModMyi's downloads section.

[mr_motta1989]

ok thank you i didnt know it was here also thank you for helping a nd making it sound and be a little bit more simple. if i have any issues ill be sure to post on this thread.

[i.Annie]

No problem

Good luck.

[Psyko]

I've had the 1015 error too with my 3GS. I got the iPad baseband installed, so when I restore I get the 1015 error, which CANNOT be fixed with TinyUmbrella. It just reboots back to recovery. However, I am able to use custom IPSW's.
If sn0wbreeze (pwnagetool for mac) can do it with 3.1.3, build a custom IPSW. That way it wont even TRY to upgrade the baseband, and iTunes wont error out. You don't even need your SHSH-blobs to downgrade from 4.0, since 4.0 for iPod Touch 2G (non-MC) and iPhone 3G only has soft-SHSH blobs for the 4.0 firmwares. You can restore between 3.x firmware freely, and to 4.x firmwares you've saved your blobs for.

[mr_motta1989]

ok so im back to 3.1.3 on my iphone 3g everything seems in order including sms but i cant send or receive mms or whichever is pic messaging i forget. when i had it on 4.0 i put in those settings manually and it worked great pic and text. now i dont know how to get it going what do i do i tired carrier bundle on cydia but after i restart it will say no service and when i removed it and restarted it connected right away