With a little spare time, my girlfriend Clara and I decided to see why my venerable Antec A300-encased Core 2 Duo Xen tower had trouble rebooting. In the process, we managed to clean her up, reorganise her internals, tie down cables and generally have a fun and terribly nerdy Saturday evening!

"Her" referring to the computer, not Clara.

When reboots involve unplugging things

Since our last move, my secondary tower has had trouble with rebooting. I could almost hear my Mac Pro chucking to herself each time I had to reach to the back of this DIY box to unplug her. In this case it wasn't a three finger salute, as much as it was a scraped knee and soft muttering.

Originally designed as an outlet for DIY fun since going to the Mac, this tower has gradually assumed more responsibilities once I started getting into KVM and, more recently, Xen. Like all good open source projects, this tower had no plan whatsoever, but evolved organically as I sourced cheap parts to fit exactly what I needed.

In keeping with my anime girl naming scheme, she became Yuki. An understated machine with more power than her outward appearance would suggest. 2008 Ruben thought that was clever.

Until last night, she would shut down just fine, but soft or hard reboots would result in a blank screen, no reassuring whirring of her hard drives and misleading LED indicators. The only viable remediation was flicking the physical switch on the PSU, waiting ten seconds, then booting her again.

That should have sounded warning bells that the PSU was shot, but like any good self diagnosing gentleman who assumes they have some horrible condition when they're manfluing, I assumed I had a shot motherboard or worse. I reseated the soft power switch cable in its pins, tested the RAM in other machines, even went out and bought a replacement graphics card.

(To be fair, the old one was noisy, and I was able to source a fanless one. For a server I’d even just serial console into if I could, this is fine).

The advantage of being an electronic archivist

So over the course of the evening, Clara and I decided to pull apart some other half working, accumulated desktops into one fully functioning unit. Turns out our mothball collecting, CD ripping tower had a far newer PSU, so on a hunch we decided to try it out.

One transplant later, and Yuki is completely back in business. She can shutdown, soft reboot, hard reboot and sleep like the best of them. I was also able to show Clara some of the finer points of DIY computer hardware, gleaned from years of introverted teenage tinkering that often resulted in serious damage and wasted money.

Moral of the story, if your machine has power troubles, shock of horrors, it may be the power supply. And if so, use the opportunity to upgrade the machine and generally have some nerdy fun :).