3G FW:3.1.2 - 4.1 Upgrade

[bobshaw]

Hi,

I have a 3G iPhone as follows...

FW 3.1.2 (7D11)
Model MB704LL
16 Gig
Modem Firmware 05.11.07

I want to upgrade and jailbreak it to 4.1 software. Right now I have the current 3.1.2 software already jailbroken with redsnow and the unlocked with jailbreakme.com

I have tried to upgrade to 4.0, 4.01, 4.1 but iTunes 10 won't let me use a CFW. I tried restoring to the original 3.1.2 FW and iTunes won't let me do that either, same erros, 21, or 1604. Every time I try I get a 21 error or a 1604 or something else.

So, I would like to know if one of the experts here can tell me how to do it. I have tried many tutorials from here, there... no success. I tried making a CFW with SnowbreeZe 2.01, 2,02, using iReb 4.xx, still doesn't work, iTunes just gives me the can't upgrade errors. I have tried using redsn0w 0.9.5b5-5 and it accepts the FW iPhone1_2_4.0_8A293_Restore_3.ipsw, starts up, goes through all the motions, SEEMS to act like it's upgrading my phone but when I turn it on it is still 3.1.2 (7D11) in my about settings on the phone.

I used these FW's to try to restore with iTunes...
iPhone1_2_4.0.1_8A306_Restore.ipsw
iPhone1_2_4.0_8A293_Restore_3.ipsw
iPhone1_2_4.1_8B117_Restore.ipsw

When I tried to restore the FW version... iPhone1_2_4.0_8A293_Restore_3.ipsw

iTunes said "iTunes will erase and restore and verify the restore with Apple"... but I am worried if I do that my baseband will be updated and I'm shot and can't unlock or JB, is that right?. And when I tried to restore the original FW to start from scratch I got 1604 or 21 errors.

Any ideas? I'm kind of stuck at the moment and paranoid I will brick my phone.

Thanks

[iYeow]

Wow, you are applying any tools that you can think of. You must know what you are doing.
Are you serious, you unlock with jailbreakme.com, you unlock with Ultrasn0w.
Do a restore again to 3.1.2 by doing the shift + Restore .
I don't think you are going to get error 1015, but if you do , then use kick out of recovery from Tiny Umbrella.
Jailbreak again with Redsn0w 0.9.4
Update Cydia
Now put your iphone into Recovery mode
Do the Shift + Restore to Custom firmware 4.1 created by Snowbreeze 2.0.2