Help! Keyboard black Macbook not working!

So I got this black Late 2006 MacBook few days ago, without a hard drive or battery. But it seemed to work fine, although the machine was VERY dirty. Today, I cleaned the whole machine on the outside, including the screen, trackpad and keyboard.

When I started it up, I mentioned that ONLY MY KEYBOARD, wasn't working anymore. No lights, no respons, nothing. My first thought was that I may cleaned it too wet, but when I shined a flashlight on it I didn't saw any wet parts underneath the keys. Some parts even seem dusty dry.

Another striking point is that my trackpad DOES work properly.
I really have no idea what is wrong with this thing or to fix it.

Anyone got an idea, please?