Sounds familiar to me. I bet it has either two or three 0's to display the LCD, right? Yes, that's used to display the CPU speed. I bet is an older case because newer cases don't usually come with those. I used to know a friend who had a LCD thing like that on one of their old 486 machines. It was 66Mhz and used two 0's to display the number "66". I would think that your LCD would be hooked up only to a motherboard that supported that feature. On my friend's board, there were a series of jumpers he set to display the 66. Basically, it's useless unless you take it out and use it for something else.