Wow the original Sprint LG Rumor. I use to be a sprint tech years ago and worked on lots of those devices. In my experience, if the LCD is black then it's a bad LCD issue. Over time dropping it over & over can cause them to go bad even without any cracks. Occassinally it would be a flex cable issue, the cable that runs from the LCD to the main motherboard. But if the dial keypad lights up then it's an LCD issue