MacBook :: Cannot Regulate Brightness (From System Preference Or Keyboard)

So Apple wanted to charge me $900 to change my broken LCD screen. I did the change myself for $86, a feat I am very proud of. Everything works great (the bezel's a bit loose and I did a little aesthetic damage to the hinge cover) but apart from that, the screen is 10x brighter than my old Rev B screen. The problem is this: I can't regulate brightness. Neither from in system preferences or from my keyboard. The monitor does, however, dim, and sleep. Is this a firmware issue? If so, how do I fix it? I would kinda' like to have control over screen brightness. After some use, this screen is really SUPER bright. I'd really like to get the brightness down to humane levels (it's shining out the back of the case where you normally don't see light).