B110 POST Failure

Sorry if this is one-too-many of these but….. it is driving me nuts. I really don’t even have any need for the computer, but defeat is disheartening.

The computer was my sister’s and died under unknown circumstances. The inside was thoroughly “felted” with cat hair, dog hair, and dust, so I am guessing perhaps heat did it in.

The symptoms are:
The power light comes on as solid amber immediately on pressing the power switch. It stays that way.
The hard drive light flashes a few times. (Is this an autonomous power-on test by the drive itself?)
The CD drive light comes on and then off. (Ditto on self-test of drive?)
I can hear both drives running while their lights are on.
The hard drive keeps spinning, with no activity.
The floppy drive light does not indicate any activity.
The CPU cooling fan and the power supply cooling fan are both running.
The power light on the motherboard is on.
The monitor stays in the idle condition (blank screen, amber light).
None of the diagnostic lights flash.
There are no beeps.
Keyboard lights don’t flash,
Optical mouse does not light.
The unidentified heat sink in the center of the motherboard gets pretty hot.
The heat sink on the CPU has good contact with conducting grease and gets slightly warm to the touch (nowhere near as hot as the other heat sink).
The power supply will shut down normally by holding the power switch.

This sounds like a very early POST failure. Perhaps even a total failure of the BIOS.

So far I have done all the stuff that normally fixes desktops. I blew out all the felt, of course. I unplugged everything, reseated everything, replaced the memory upgrade with the factory memory, removed the network card and reseated the CPU. (How does that chip make contact with so little movement of the seat?) I removed the CMOS battery for half an hour, just in case it had gotten scrambled. I used the reset password pin procedure. I have tested the power supply with a meter and all (no-load) voltages are correct, including the Power OK signal. The connection signal to the monitor seems to be correct, since if I unplug the cable the monitor displays the message about the open connection.

One side question: If the problem turns out to be the CPU itself, will a Celeron D from a notebook work in a Dimension? I can find any number of them for about $2 and at that could try one just to see if it is a problem. (Remember, defeat might be an option, but not a good one.) The only difference I see on the Intel specs is that the notebook version draws 65 watts, the desktop draws 73. Just off hand I would guess a notebook CPU would work in a desktop, but not the other way around. Is that a correct assumption?

Bottom line:  Is the machine basically a paperweight at this point?