Someone at work asked me to take a look at their old iPhone (which was given to them) and, for the first time, I've not been able to unlock it properly. I have it on 3.1.2, but it simply reports "no service" with any SIM chip inserted. From what I gather whoever originally messed with the phone may have corrupted something. It was using 2.2.1 (I believe) and had no service issues. It has never worked properly once they attempted to unlock it (always no service), but it had been working just fine when it was a legit AT&T phone. So, what could have been done to this phone and is there any way to bring it back to its original state? Restore the baseband etc. to an original release? I would like to try starting from scratch.