Hi, so i bought a 2006 white macbook of my friend for 150, ive had it about 9 months or more now and everything is fine apart from the screen often looses its brightness and the screen goes black, the laptop is still on and the screen can be seen when a bright light is help up to the screen, i am able to see the screen again by using the brightness buttons to turn brightness all the way down and then up again. sometimes it wont happen for hours and sometimes it goes through a stage immediately going back off, any advice would be appreciated as I didn't think there would be much point in taking it to the genius bar due to the age of the machine ?