How do I put the light feature back on the keyboard?

PLEASE HELP ME..HOW DO I PUT THE LIGHT FEATURE BACK ON THE KEYBOARD? IS THERE A FIRMWARE OR DRIVERS SOFTWARE? THERE ARE NONE . AND THE DISPLAY LIGHT IS DIM...HOW TO MAKE IT BRIGHTER? THANK YOU. MIKETTE EVERYTHING ELSE IS PERFECT

15" Powerbook G4 1.25GHz (FW800 – AI)

The 15” PowerBook G4/1.25 (FW800) (M8981LL/A) features a 1.25GHz PowerPC G4 processor with 512k on chip level 2 cache and 512MB of PC2700 DDR SDRAM. They come standard with an 80 GB (4200 RPM) Ultra ATA/100 hard drive, a slot-loading 2X DVD-R/CD-RW SuperDrive, one Firewire 400 and 800 port, built-in Bluetooth 1.1 and AirPort Extreme (802.11g). An ATI Mobility Radeon 9600 (4X AGP) graphics card with 64 MB of DDR SDRAM powers the 15" widescreen TFT display (1280x854 native resolution). The PowerBook G4/1.25 15" (FW800) has the fiber optic ambient light sensor that automatically measures ambient light and works with integrated software to adjust keyboard illumination and screen brightness based on user preferences. The PowerBook G4/1.25 15" has a faster processor than its predecessor, twice the default RAM, a larger hard drive, an upgraded optical drive, and AirPort Extreme (802.11g).