I couldn't sleep last night, so I sat down and went through my box of bits. I had three old motherboards with different faults. I now have two working motherboards. (unsoldered and swapped the crystal and the CPU to one and the BIOS and memory sticks to the other).
I then combined the bits of two old cases and made a good PC tower. The fans were noisy so I pulled a couple of old spares out of my collection. One has pretty blue LEDs when it operates. I also removed a couple of broken switches and swapped them for working ones from the unused case.
The motherboard does not have network interface, nor video outputs etc. These have to be bolted on in the form of daughter boards.
As this was going to be a Server, I rummaged through the box of old video cards and pulled out a Verge S3 card. That works wonderfully.
I pulled out an unbranded 52X CD drive and screwed the side runners onto it and inserted that into the slots. I found a load of old drives in one of the boxes and made a RAID array of 4 identical drives (320 GB x 4).
Then I found my old NT4 Server software. Spent 2 hours formatting disks, loading drivers and installing the software etc. Had to find some 8139 drivers for the network card, but I had some in the files library.
I now have a working NT4 Server which has just logged itself onto the network as the Backup Domain Controller. I have a complete spare identical unit, in case of breakdowns.
1 GB RAM, 1GHz processor. That is incredibly fast for an NT4 server that will check people's credentials and serve up some files. It is now supporting the Creators Forum Server.
Yay!