Mouse hiding in cable tray cheesed off its bemused user

Who knows where all those cables go anyway?

On Call Welcome once again to On Call, The Register's ongoing chronicle of IT incidents that readers have managed to survive, divert or diminish, while emerging with reputations intact.

This week, we meet a reader we'll call "Grant" who was summoned to a user’s desk to address an issue described as "My mouse pointer is twitching."

Grant visited the user, who moved the mouse pointer to a box – at which point it did indeed start to move despite no human hand upon the digital rodent!

Testing a mouse known to be in good working order was the obvious first step towards a fix. Grant had one with him and plugged it into a USB port.

The wandering pointer recurred.

Grant tried another USB port. The pointer again started to move.

At this point Grant sat down in front of the machine, rebooted it, checked the user's existing mouse and his known good mouse.

And seemed to have solved the problem.

But as Grant turned to leave, the user rolled his chair back under the desk … and proclaimed the problem had recurred!

At this point Grant decided to check the Windows Device Manager, which revealed a second mouse – a trackball, actually – was connected to the machine!

But the trackball had fallen off the physical desktop into a cable tray. When the user rolled under their desk, they nudged the tray, which jostled the trackball, which made the on-screen pointer move.

How had the trackball been forgotten? Grant learned of a user who, in the age of PCs that offered a single PS/2 port, routinely swapped a mouse and trackball … and continued to do so once both the PC and the pointing device migrated to USB.

Once the wonders of USB became apparent, the user moved on, but the trackball was left in place and eventually fell – literally – into disuse and the cable tray. The inheritor of the PC believed the machine had no mouse, requested a new one and managed to connect it without noticing the presence of the trackball.

Grant suspects that arrangement may have persisted for years before he came along.

And the sting in the tail? Grant's employer blocked the front-facing USB ports on its PCs, which was the reason the twin rodents were never detected.

If you've ever discovered hidden hardware that gave colleagues hell, let us know by sending a message to On Call. Yours truly has resumed custody of this column and inherited a modest mailbag, so all contributions are welcome! ®