"These instructions currently only work with iNdependence on the Mac. It will unbrick you iPhone -but- will not restore cellular service, only wifi.
Here are the steps:
- Make sure you have a copy of the 1.0.2 firmware handy in ipsw and decrypted form
- Reboot iPhone holding top (power) and home buttons *BUT* release the top button 10 seconds into it (right after the screen goes dark)
- The iPhone screen will appear to be off, but start iTunes (latest version worked for me on the Mac)
- Option+Click restore and select the 1.0.2 firmware ipsw
- The phone will restart and error out at the end with an unknown error 1013, this is expected
- Restart iTunes and let it get to the screen that says you have an invalid SIM
- Launch the latest iNDpendence
- Jailbreak the phone using a decrypted 1.0.2 (it will flash all sorts of error, but stick with it)
- Activate the phone
- It will show the SIM error but you should be able to get back in
I installed AppTapp afterwards along with the BSD subsystem and SSH, all working over wireless only.
So far, bbupdater will not revert the firmware."