It’s the early 1970s and this shop decides to upgrade to a faster card reader for its mainframe. And so the consultants arrive from the BIG mainframe provider. But the installation doesn’t go well, says a pilot fish on the scene — every time they run a deck of punched cards through the new card reader, the mainframe crashes.

Support technicians come and go. Each one tries to troubleshoot the problem but comes up empty-handed.

Then, on a Friday afternoon, the mainframe maker’s design engineer arrives with tools and an oscilloscope. He attacks the situation all day and is still hard at work when the shop’s employees go home for the weekend. And on Monday morning the employees arrive see the card reader mostly disassembled, the oscilloscope’s probe attached to the card reader’s ground wire, and the design engineer lying on the floor — laughing hysterically.

For a long time, he can’t even talk, but he eventually tells them he had been struggling with the card reader all weekend and was thoroughly exhausted. But he did manage to discover what the problem was: The wrong kind of grease was put on the roller shaft bearings at the factory. Special conductive grease was supposed to be used in order to prevent static charges from building up. The ordinary grease that was used was an insulator.

Thus the card reader’s transport mechanism was acting as a Van de Graaff generator, accumulating a little more charge from each card that passed over its rubber rollers, until thousands of volts were reached. Which of course zapped the mainframe like a miniature lightning bolt when it discharged into their common ground wire.

The shop eventually received a working card reader, with conductive grease.

Sharky gets a charge out of your true tales of IT life. Send them to me at sharky@computerworld.com. You can also subscribe to the Daily Shark Newsletter and read some great old tales in the Sharkives.