David,
Sounds like one of the connectors on the power supply cable to the fan
has a bad connection.  Is the power cable to the CPU fan the same one
that feeds the hard drive?  Pull the connector apart and check the
contact pins in both male and female connectors.  You can sometimes
"scrunch" a female connector that is open a little too far so that it
makes better contact with its male counterpart.  Use a jewelers
screwdriver to force the female connector to a more closed position.

Jerry Rasmussen
--------------------

David Gillett wrote:

>   When I got the machine open and fired it up, I noticed something
> rather scary.  If I moved the power lead for the CPU fan around, the
> fan would slow down and speed up, and when it sped up all the way,
> the hard drive would "wake up".
>
>   My revised diagnosis is that the power supply has become
> unreliable and/or inadequate.  This is something that others seeing
> this kind of symptom should probably be aware of and check.
>
> David G