Monitor turning itself off

I've run into a very nasty problem with my macbook (late 2007 normal macbook model I think). Whenever it closes, the monitor goes black. This is normal. What isn't normal is this: whenever I open it and then either start it/awaken it, it gives me the screen... and then the monitor turns the brightness off again! This happens randomly, I have to close and open my screen quite a few times to get it to work-even if I restart the computer. I don't what's causing this, or how to fix it, although I have a hunch that it's the hinge on the back... I have the tools and instructions needed to open my machine up if it's a fairly simple fix, but I need to know what's going on first. Please help?

Before you decide to start taking your MacBook apart, try resetting the SMC first as that controls the display on and off when opening and closing the lid. See this LINK.

Nope. Doesn't help. Just tried it, and the problem is still there. I really think it's hardware related, as it just started to turn up after I tried to replace my disk drive (the operation failed solely because the replacement part was the wrong one; taking apart and putting it back together went perfectly, or so I thought... then this problem shows up a few days later.) I really need help-now I can't get the display to stay bright at all, and although something does show up on the screen, it's so dim I can't see it at all!

EDIT: I think it's getting progressively worse...

Update: I can get the monitor to run or a little while by dropping the brightness to nothing, and then raising it, but then it keeps on dimming it for some reason... I have no idea what's going on.