Alan Zisman -> August Abolins said..

 AZ> You could try attaching a heat-sink in place of the fan or
 AZ> replacing the fan with another... or look for an AGP card with
 AZ> Mac support.


I started to take the fan assembly apart.  I'm going to try a few drops of
sewing machine oil at the center hub and through the sides.

If that fails, I would rather unplug the fan than hunt for a replacement. 
The video chip seems to already have a very robust heatsink. The fins were
a bit clogged with dust, but now it looks pretty good.

The cost and guesswork of finding a replacement card is prohibitive.  Based
on this info:

"On December 2, 1999, Apple replaced the 350 MHz "Yikes"
with a Sawtooth model of the same speed. Although selling for the same
price ($1600), the newer model has DVD instead of CD-ROM, AGP video instead
of PCI video, and the ability to accept an AirPort card."

Since the PPC that I am working on has DVD, I'm assuming that I have the
"Sawtooth" model.  Further to the above:

"Because this model was created before Apple adopted the ADC port
(which provides power to an external monitor), the Sawtooth G4 may also be
incompatible with AGP 4x and later cards that include a retention tab.
Because of voltage differences between the AGP 2x and 4x specs, newer cards
may also be electronically incompatible with the Sawtooth G4."

I understand that there is an adjustment in Settings where I could control
the temperture thresholds when the fan kicks in. I may look into that too.

--- Thunderbird 2.0.0.24 (Windows/20100228)