I bought this Iphone from someone who said everything was in perfect working condition and before I bought the Iphone I put my sim card in it and played around with it for a few minutes. It seemed like everything was working fine and so I gave the guy the money for it, but when I got home I noticed the Iphone said no signal and since then it seems to want to stay at "no signal" for 98% of the time. When I tried contacting the person who sold me the phone, he just ignored me, he wouldn't return my calls/texts, nothing. So now I'm stuck with a defected Iphone that I paid a lot of money for. I thought maybe it was just because I'm using it with tmobile and it wasn't unlocked properly, so then I inserted my boyfriend's sim card into it, who has AT&T and it does the same thing with his sim card, even after I restored it with itunes and took the unlock/jailbreak off of it. Any ideas what this problem could be would be very helpful. Thanks for taking the time to read my thread.