Question : Problem: stuck an att sim card in an unlocked iphone 3g

stuck a prepaid att/cingualr sim card in an unlocked iphone 3g,  "no service" on the top left hand side

Answer : Problem: stuck an att sim card in an unlocked iphone 3g

Then I am sorry the phone has not been unlocked.. It is trying to activate through iTunes.. This wont work unless you have a vlaid account with your celluar providor..