I have an LG run of the mill cell phone. Two days ago I turned it on and the AT&T logo was the only thing that appeared. It was almost as though it was froze on the start up screen. So I called AT&T and they sent me a new one which I got today but the same thing is happening. I took it to the store and they said the phone was just "bad." A brand new phone, same model, with the same defect. They tried replacing the battery and all. Would a SIM card have anything to do with this?