Kettle boiled - network went down: how a cup of tea helped fix a computer system

An engineer from Norsk Data solved the mystery behind the frequent crashes of the Wordplex word processing system in an unusual way.

The story took place in the 1980s. Kevin, an engineer at the Norwegian company Norsk Data, which specialized in mini-computers, encountered an unusual issue. He was called to a client’s location to repair the Wordplex word processing system, which was constantly crashing. This system, powered by an 8-bit Z80 processor, included a main computer with a 10–20 MB hard drive, a 5¼-inch floppy disk drive, a green monitor, and two terminals connected via RS-232, which had no data storage of their own.

Despite two previous visits, Kevin was unable to resolve the problem. Suspecting electrical issues, he brought an electrician with him this time. Upon arrival, the client offered them tea, which turned out to be a pivotal moment in the investigation.

As soon as the electric kettle was turned on, Kevin heard two sounds: the kettle clicking and the Wordplex system shutting down. Suddenly, everything fell into place—the cause of the crashes lay within the electrical network.

The electrician quickly identified the issue. It turned out that the client had recently upgraded the wiring, but the work was poorly executed. When the electrical load increased—such as when the air conditioning was turned on, elevators were in use, and all employees were present—the wiring could not handle it. The kettle’s activation became the tipping point, overloading the electrical network and shutting down the computer system.

It is important to note that Wordplex was quite demanding regarding the stability of its power supply. Its clustered architecture with a main computer and connected terminals made it vulnerable to sudden voltage changes. When the electrical network was overloaded, it led to data loss and system failures in the word processing application.

Thanks to this discovery, Kevin and Norsk Data absolved themselves of responsibility for the hardware issues. The problem lay not with the Wordplex equipment but rather with the client’s electrical network. Incidentally, the kettle did work, and Kevin eventually got his tea.