MacBook 2007 Replaced Inverter and still no backlight.

Hi! I'm having an issue with my Macbook 2,1 Mid 2007. I dropped it and the backlight is no longer functional.

I live in NYC and took it to a place called TekServe and they suggested as did many posters on iFixit that I change out the inverter and cables, which I did. I've tried plenty of things like starting in safe mode, PRAM resets, and diagnostics mode.

According to Diagnostics, there's nothing wrong with my laptop. I can power it on and it loads perfectly, the lcd screen functions fine and I can see the desktop. I am even writing this message from the computer; the only problem is that the screen is very, very dark and I have to tilt it into better lighting or hold up a flashlight as I use it. It connects to an external monitor and works perfectly also. I'm just not quite sure what else if anything to exchange. I keep reading about changing "a bulb" but no real details or posts on how or where to get parts to do so.

Can anyone provide some more insight?

ALSO! I did upgrade RAM recently, 2-3 days before the fall. I now have a total of 4GB RAM currently (2x2GB) and it seemed to be working perfectly and much faster also but I did read another post where the OP says they changed RAM and the display backlight stopped working. seemed farfetched but is that really possible? Should I revert back to the standard 1GB?