Sorry for YAXFB post (yet another) , but If anyone is sitting on the 
fence waiting on doing the Apple Mirror Drive Door Power Supply 
Exchange Program, go for it. I have the 867 Dual.

Amazing change. Now instead of the diesel, there is a quiet hum, with a 
semi-annoying but so-far tolerable beat frequency.

You can now hear the hard drive accessing, and that is something you 
couldn't hear very well at all before. And you can hear yourself type, 
and breathe, and you can't hear it 2-3 rooms away down the hall anymore.

Not bad at all for $20USD other than the 4 week wait. There were also 
no emails about the order status. It just showed up. (G4Noise.com has 
complained about that aspect of the operation.)

You get to keep the parts, or otherwise dispose of them per your local 
jurisdiction, which in this case, means the power supply will now power 
up some big stepper motors, and the other fan can cool the stepper 
drivers. Perhaps.

Since I know some of you have the noisy variety of G4 tower (MDD) you 
may wish to update to reduce the noise level. Wow, this is an amazing 
difference. I may yet become as tolerable. :)

Tedd, send me $20, and I'll cut my noise in half too.  \ 8^ )

Gratuitious Thankee's,

Robert Bob