Why does my TI-84 plus calculator say RAM cleared?

Why does my TI-84 plus calculator say RAM cleared?

When turning on my calculator, the screen displays "RAM cleared" and "press alpha F1-F4 to locate shortcut menus." After pressing alpha F1-F4 there is no change in the display and none of the buttons appear to work or change the display. The only way to get the display off is to pull out the battery :( Any ideas on how to fix this?