MacBook turns on, but MacBook screen stays black

I have a A1181 family, model no MB061 MacBook, with a clean install of Mac OS X Snow Leopard. I recently turned it on and it starts fine as the apple tune plays however, the screen remains black. I have checked whether it is the backlight and it doesnt seem to be that problem. However, if I plug my macbook into a monitor using the mini display port and turn it on, I can see everything and it runs Mac os X snow leopard and functions correctly. Nothing appears on the MacBook screen though.

So I then removed Mac OS X and installed ubuntu on the Macbook, and weirdly the MacBook's display works absolutely fine when running ubuntu which is very odd.

Does anyone have any ideas as this problem is driving me up the wall. Thank you 🙂