Had a call from a company who said their NetWare 286 server (the one with the grid display?) was down. I asked them to check it was switched on and they said yes - they could see the display. Got to site and noticed that what they could actually see was the grid burned into the monochrome display and the server was actually unplugged. Following the extension lead that had been plugged into the servers plug socket, the culprit was found drilling holes in an adjacent office.
I got called out to a British Rail office in Croydon who couldn't login to their Torus server. They'd had new carpets fitted over the weekend and the fitters had cut the coax cable at each floor point.
I remember a guy who used his IBM ATX with a missing drive panel as a useful ashtray.
I got a call from an angry user whose Wang Pro was making a continuous beeping noise. When I got to the office it was sitting on the pavement outside after leaving the building via a first floor window.