the screen on my macbook pro has recently stoped working. i fear it is because i close the laptop without closing a streaming video, and it has not gone to sleep, instead overheated the motherboard. i there are no lights working, and when i open and close the laptop screen the sleeper light goes from dim to bright with the up and down movement of the screen. it makes the usual start up sound, but then the screen dosen't respnd. is there anyway i could check to be certain of the problem?