G3 iBook hardware problems

[Beartooth]

My wife runs only YDL3 on her machine. Recently it took to dimming the
display a lot. An Apple-fancying friend who happened to pass through tried
a couple things (I didn't watch, alas!) that didn't help, and suggested we
reboot to OSX and set the brightness control Apple's way (whatever that
is); but we never got that far. She rebooted -- and now the brightness is
OK -- but the machine makes a strange faint whine, and the left front
smooth place in front of the keyboard is hot to the touch. Not hot enough
to be unpleasant, but definitely hot.

I'm the nearest thing to support she has, and I don't speak hardware. What
do we need to do? Take it to a shop?

-- 
Beartooth Implacable, curmudgeonly codger learning linux
Remember that I know *very* little of what I'm asking about!