Freaking Laptop screen randomly going black!

My Compaq Presario 2500 laptop screen used to just snap off on startup if I wasn’t actively moving the cursor (touching the touch pad), but now it just randomly shuts off! Though not completely. If I tilt the screen just right and shine a highpowered light on it at just the right angle, I can see pretty clearly whatever the beam of light hits. Problem is, doing that doesn’t do much for productivity. And my laptop’s been outta warranty for about a year.
So my screen goes black, I have to use a flashlight to save critical info before I shut down, and am always living in fear of it shutting off just to make my life hard at any moment. Before I take it to a bunch of computer store guys who want to gouge me, could any one give me a hint as to what this problem is and how much fixing it should cost, so I don’t agree like a brainless booby to everything they say and end up getting bankrupted?

And now the thing’s developed a new complication. I use wireless internet, protected by avast, and haven’t had problems with it. EVER. Now all of a sudden, when I enable it, the initial popup says it is enabled but network connections say it is still disabled. I run netscape, and it mostly loads the page, like my internet is up, then hangs and won’t shut down, whether by task manager or other means. It doesn’t hang my whole system though, I can still do other stuff, but I can’t get on the bloody internet. Is this related, or am I experiencing the rebellious teenage years of my computer? Or possibly its final demise?

AIGHHHHHH.
Thanks.

It can be something so simple like a loose inverter card or a loose cable assembly, or any of these two may have gone bad and both are quite cheap, or it can be a failing screen which would be wrost. These are your 3 primal culprits to watch for IMO.