No service after blackra1n on at&t

I was on 3.1.3 and downgraded to 3.1.2. i put in the sim but get no service. It did jailbreak. When I downgraded, it would do to the plug into itunes screen. I then jailbroke it and it worked. But no service. It will show one bar. ANy ideas?

 

This method will get your carrier signal back when downgrading to a 3GS to 3.1.2. I've only gotten this method to work on XP so if you have a XP machine great. Feel free to give it a shot on a Mac or other Windows.

1st restore again to 3.1.2. except when it says connect to itunes follow these steps:

1) download iRecovery iHackintosh iRecovery Package for Windows & Mac.rar from here.

2.a) To start iRecovery on mac, simply open the command line applicaiton(Terminal), and then DRAG the iRecovery file from the location you've extracted it and DROP it inside the Terminal window and add to the end of the command line that is automatically written '-s' so it should be 'irecovery -s'.

2.b) To start iRecovery on windows, first extract the iRecovery to the root directory "c: \" of your hard disk, then run the exe file 'libusb-win32-filter-bin-0.1.12.2.exe' already contained in the archive downloaded in step 7, then open windows command line application 'cmd' and type 'irecovery -s' while you are at c: \

*** Note for Windows 7 & Vista users : BEFORE INSTALLING libusb-win32-filter-bin-0.1.12.2, right click the file and set it to run under compatibility mode for Windows xp sp2.

3) When you are left with command line empty, type in the following :
setenv auto-boot true "hit enter"
saveenv "hit enter"
/exit "hit enter"


4) Reboot your iPhone by pressing and holding the sleep/power button and the home button until the iPhone display turn off.

5) Have a SIM card inserted in your iPhone.

6) Wait until the iPhone get ACTIVATED by iTunes and then you can jailbreak it

 

Also here's anoter method I did get to work with Window 7

This is from gaetanospqr’s post on modmyi:

“first download quickpwn22 and unzip to a folder or desktop. I’ll tell you when to use this, this will get you out of recovery and give you your officalcarrier.

Down grade to a downloaded custom 3.1.2 ipsw, open itunes plug your phone in and put your phone in dfu mode not recovery mode, hold sleep and home 10 seconds let go sleep and contiue to hold home 10 seconds till a pop up on itunes tells you you’re in recovery mode and need to restore in order to continue,

hold shift and click restore same time navigate to custom 3.1.2 ipsw file and restore when it’s done you will get an error 1015 or 1014, that’s ok that means you’re backed up on cydia and it’s communicating, the you will be inrecovery mode where you will see disk and connection cord on screen, just click shift and restore and insert custom ipsw file again hit restore.

same error message 1015 will appear, now start quickpwn 22 while your still jacked in on itunes, it will give you a message that says hold sleep and home for 15sec then let go of home and continue to hold sleep for 2 seconds, this will get you out of recovery and your officialcarrier back, next run latest rc3 blackra1n jb, and it’s done~! downgraded to 3.1.2 with firmware 5.12.01 and official carrier with jb”