4s baseband chip wont work after ios 6 update

hi, i got this itunes error (-1) when trying to update my iphone 4s from ios 5.1.1 to ios 6. i have tryed many internet solutions but none of them worked. i got to the conclusion that the baseband chip is not working. it's there some way to restore to any of the ios versions without the baseband chip, like just for running apps.

any solution will help

thanks

mac os x 10.8

macbook 2009

iphone 4s (restore mode)