I need help! My laptop surface keeps going black!?

Might be a dying picture card. Can you unmoving hear the computer playing sounds and such? Generally provided the mechanism is still running and you can hear everything functioning, its likely that the video card is overheating then shuts down when it warms up and the pins come off the board. If this is the case, it'll eventually stop working entirely. Back up your data just in case and have it looked at.