Pilot fish walks into his small lab at a big computer maker one morning and finds one of the building’s maintenance guys packing up his tools. So fish chats with him for a bit and then asks what he had been working on. “I had a work order to change the wall power for the lab’s printer from 240 volts to 120 volts,” responds the maintenance guy.
“That’s odd,” says fish. “The printer’s been happily plugged into that outlet for years.”
Maintenance guy shrugs and leaves. Almost immediately, one of fish’s co-workers announces that the printer is down.
Fish opens the printer’s cover and looks at the power plate. Sure enough, the printer is built to use 240 volts. So when the printer vendor’s repair guy arrives to troubleshoot the problem, fish immediately fills him in about what the maintenance guy had done.