IBOOK G4 Display Brightness Problems

Hello, I am puzzled over a problem with my IBook G4. The display on the machine went bad. I put the machine on an external monitor to make sure all of the inner workings were ok and they were fine.

I replaced the lcd screen with a new one that I got on Ebay. I had no problems reinstalling the screen and am sure the 2 plugs that needed to be plugged back in were.

Upon rebooting the Mac the new screen does work but it is too dim. I looked in all the settings and cannot seem to find a place to lighten it. I have researched online and found others that had this problem but really cant find a solution. The F buttons do not work holding or not holding the fn button. There is no slider bar in any of the settings that I can locate. At first the F buttons did not work for the sound either but I since have got them to work. The ones for the display brightness still do not.

Does this mean I got a bad screen or did I do something wrong? Any help from anyone who has had this situation arise or experience with this problem will be greatly appreciated!! Thank you.