To err is human. To really screw things up requires a wayward screwdriver

Plug and play, 1970s style

Who, Me? Sometimes a shortcut can result in a short circuit. And occasionally a shortened career if one lacks an understanding boss. Welcome to another Register reader confession from the Who, Me? archives.

The latest tale takes us back to the 1970s, "when computers really were computers and a megabyte was a LOT of data," recalled today's contributor, Regomised as "Mark."

Our hero was a newly minted site engineer, working shifts at a data centre housing multiple mainframes running 24 hours a day, seven days a week.

The beasts in question were of the ICL 2900 variety and worth millions (even in those days). Now long obsolete, some units still endure in museums – The National Museum of Computing, for example, has a 2966 replete with three original ICL terminals. The Central Processing Units occupy five large cabinets alone, and a dedicated mains power supply is required to keep the behemoth supplied with juice.

Which is where Mark came in, some 40 or so years previously when the ICL 2900 series was at the height of its power.

"One Sunday morning," he told us, "towards the end of a night shift, the lead engineer said we would carry out preventative maintenance on one of mainframes.

"Even now the word 'preventative' starts a nervous tic..."

It was a simple task. Work through the 30 or so cabinets and clean the fan filters and check the PSUs. Plus any other bits of maintenance that needed doing.

As he was making his way through the boxes, Mark noted that an indicator light on one panel was dead. "No problem!" he thought and, with the enthusiasm of the newly minted, decided: "I can change this without a power down."

The indicator was powered from a terminal block, along with a great many other connections. As one would expect, Mark took great care when removing the old neon. The same care was taken with screwing in the new one but... it turned out it wasn't enough.

The screwdriver slipped...

"There was a flash brighter than the sun, and the noise of a large mainframe juddering to a sudden halt," he said.

"I was out of the computer room doors and walking back in with a puzzled expression on my face by the time the operators realised the thing had crashed."

All in all, the mainframe was down for 24 hours and displayed a voracious appetite for spare parts before finally coming back to life.

And Mark, his misdeed noted, had to face the music.

"Amazingly," he said, "I was only given a reprimand rather than ending my IT career... the site manager saying that my intentions were good, and I would have learned from my mistake."

Ever dropped a screwdriver where you shouldn't? And was your boss as understanding as Mark's? Let us know with an email to Who, Me? ®