Powerbook G4 Repair Question

[forkedt]

I just picked up a PB G4 (Model M8407) from a co-worker. Their dad spilled water on it but it powers on fine.

Problems so far:
The Screen Backlight is dead (shine a bright light at the screen and you can see the desktop is one when powered up)

The Trackpad does not respond to input.

I have not been able to test the USB ports (going to try a usb mouse tonight) or CD drive yet. The Keyboard does function - I can input commands, and the Speakers work well enough the "Beep".

I am not overly familiar with Apple computers but would like to salvage this if possible. What I've learned so far seems to point that the Screen Backlight is linked to the Inverter Board, however I've seen nothing linking the Trackpad to anything...

If I replace the Inverter Board is it likely to fix the Trackpad as well, or does this sound more like the entire Logic Board needs to be replaced?

Thanks!