Brightness Display Settings Changing Automatically

I use a G4 iBook.

I've been occassionally noticing that my monitor will become dimmer. When I check my brightness display settings in the System Preferences I find that the setting has somehow gone down since the last time I've adjusted it. It's not a problem I deal with everyday but it is frustrating and distracting when it does happen.

Does anyone know what causes this and if there is a way to prevent this from happening?

It's a pretty good chance it's your backlight or inverter. Either way it's an easy fix, ifixit.com.

im new here but i have read many threads like this and it seems that reseting the pmu is usually the fix.

if i were you, i would got to apple support and download all the latest updates, reset the pmu and see if it fixes the problem. hope this helps.

sorry this solution is for the macbook pro, it might work with an i book, well it wouldnt hurt to try.