|if you have one available, try hooking the mini up to an external monitor...this will let us know if the video chipset is still working. A few things come to mind.|
1. Netbooks and Laptops have a presentation mode toggle (usually Fn+some F-key) that will disable the notebook's lcd and instead output to an external monitor. I have an asus that merely has the choice of turning off the display, regardless of connection to an external display...essentially, after checking to make sure the graphics are working, you might try inspecting the keyboard for Fn button combinations that have to do with the onboard display.