Hi, Newbie here and I don't know whether this issue has been previously discussed. I had an iphone 3gs 4.1 which mistakenly I restored to ios 5.0.1. Along the way I think base band also got updated to 5.16.05. Somehow I was able to downgrade iOS using custom IPSW to 4.1 with Cydia installed on it. I thought it is already jailbroken. But it is not detecting any SIM card. Please help.