Weirdest Problem ever! What's with my display

Ok, this is the strangest thing ever. It has been happening to me for a about a week, I dunno why.

Whenever I'm using my macbook (13.3 inch black) with 10.5.8, randomly, without any given warning, the screen will go black. Why? I don't know. It also occurs when I wake it up from sleep and turn on my computer.

So now you ask, well how do you use it? Well, the only way I can get the screen get back to life is by holding my Macbook under a lightbulb, and with the screen being very dim, scroll up to sys preferences, press display, and drag the brightness bar up. So you ask yourself, why do that when you can just press the brightness button? As soon as this problem occurs, the brightness button stops working. As soon as I drag the slider, and the computer comes back, it works again.

Why is this happening? It' really hard to use my computer, and it's really annoying. I have tried doing the PRAM reset, and the thing where you take the battery out and hold the power button. Please help!

 

I really dont know where auto brightness is?

As soon as the screen goes black the all the keys are useless, and have no affect. As soon as i slide the brightness up in the preferences, the button works again.

 

ok, i have been reading around the forum. I saw that people are having with the inverter cable, which affects the display when you move the lid. Nothing triggers it, i have tried moving my screen, running programs, it just happens randomly.