I bought an i phone 3G, 4.0.1(unlocked) from ebay. When i inserted my sim, a message "No SIM" showed up and i tried many times. Is it necessary to turn off and on before and after inserting SIM?Do i need to activate it again? Power button doesnot work,as the seller mentioned in his/her post, may b jammed or whatever the reason. But i thought i hav nothing to do with power button 'cause it will automatically turn on connecting it with PC, so i decided to go with it. Then i reset the all settings including network setting. Now I have no clue it has gone to default stage or still can function as unlocked??

To sum up, how to fix 'NO SIM' error? is it still unlocked after resetting all settings?? how can i turn off without using power button? is it possible to do so by syncronizing with PC?

your help will be appreciated.