That old box of tech junk you should probably throw out saves a warehouse

On Call Reg readers in the US and UK are about to enjoy long weekends – perfect occasions, and timing, for a spot of spring cleaning. But as we discover in this week's edition of On-Call, our weekly reader-contributed tale of tech support traumas, that might be one chore it's wisest to set aside.

To understand why, meet a reader we'll Regomize as "Roland" who told us he does IT support and admin at a publishing company's warehouse.

The facility is one of those affairs with lots of conveyor belts rattling around to move books from racks to trucks, and back the other way.

"The conveyor system is controlled by a redundant pair of servers that remotely interface with the actual industrial conveyor control panels which are spread throughout the facility," Roland explained.

Roland's life became particularly interesting when one of those control panels failed, and it became impossible to move or sort stock.

"Without this we're effectively dead in the water," Roland explained.

The publisher's maintenance team quickly found the cause: a failed DC to DC power supply in one of the control panels.

Suppliers were summoned and told to supply a replacement part – pronto.

The best they could do was 24-hour delivery.

Which was when the maintenance team did something very sensible: ask Roland and his tech colleagues to solve the problem. Could they, perchance, provide a 2A 5V DC power supply?

Roland knew that plenty of computers have 5V rails, so went looking for something to do the job.

Sadly, this particular publisher used desktops that employ non-standard power supplies with only 12V and 3.3V rails.

Roland therefore dived into That Box Full Of Old Tech You Should Probably Have Thrown Out But Kept Just In Case. We all have one. His particular TBFOOTYSPHTOBKJIC even contained a stash of dusty old external power bricks.

"I finally found an ancient Sun Microsystems workstation in our datacenter that had an ATX power supply unit," Roland recounted, adding that he thinks the Sun box was an Ultra 5 workstation. Whatever model it was, the machine had PS/2 ports for mouse and keyboard, and an ATAPI optical drive.

• Cheapest, oldest, slowest part fixed very modern Mac
• Is there anything tape can’t fix? This techie used it to defeat the Sun
• Datacenter fire suppression system wasn't tested for years, then BOOM
• Thanks for fixing the computer lab. Now tell us why we shouldn’t expel you?

Roland yanked out the power supply, one of the maintenance team wired it into conveyor belt control panel, and together they jumpered the PSU_ON pin to ground – a clever hack to force the PSU to power up and stay on.

It worked.

Which means we can make an esoteric pun by observing that a Sun workstation "sparced" the warehouse back to life. Because Sun used Sparc processors – geddit?

Maybe you hadda be there.

Roland says his colleagues in maintenance learned a lesson and now keep spare PSUs to hand.

But techies already know this – which is why TBFOOTYSPHTOBKJIC exists. And also why you might want to skip spring cleaning this weekend.

Have you found spares in unlikely places? If so, click here to send an email to On-Call and we might feature your story here on a future Friday. ®