hello there everyone. i just got an iphone3gs from a friend but since im still new to this kind of device,and i cant seem to use any simcard,so what should i do? apparently my friend said she accidentally reset the phone. it could use simcards before,and is already jailbroken(i think). so do i have to send it to a shop for repair or can do it DIY? if send to shop for repairs,how much would it cost? thanks a bunch!

how to check both IOS and baseband?sorry,noob here.