When Power Supplies Attack!

When Power Supplies Attack!

Where there's smoke, there's usually fire—except inside your computer's case. There, things may get dangerously heated without your ever glimpsing a flame.


When we were testing out a power supply in PC Labs the other day, our noses knew right away that something was up—specifically, the temperature of one or two of the components we were working on, judging by the not-so-lovely overheated-metal odor we couldn't escape.




Normally you'd expect a computer emitting wisps of gray smoke and sinus-offending miasmas to not boot. But ours did—and perfectly well, which is why it took us several seconds longer than it usually might to figure out the problem.

One of the cables attached to the system's modular power supply had malfunctioned. And, when that happened, the components to which it attached, shall we say, did not react well. The SATA data connector fused itself to the system's optical drive, but came apart with enough tugging—taking the entire connector with it. The hard drive, attached to another connector on the same cable, looked completely unscathed, but steadfastly refused to boot in any of the three systems we tried it in.




In addition, the SATA data cable connecting both the optical and hard drives to the motherboard had been affected as well, melting and blowing out two of the motherboard's SATA jacks. This is probably because the residual heat from the power cable needed somewhere to go. Still, we were more than a little surprised to see just how bad the damage was to a cable that had no direct contact with the PSU.





We're still trying to track down the exact cause, but it's not as easy as we thought it would be. Given the complete and utter annihilation of the cable, and the fact that the other, non-modular power cables from the PSU still work just fine, it may have been some sort of really unfortunate mismatch—this cable and this PSU just didn't know how to communicate with each other and thus had a literal blow-up.






We contacted representatives from two major power supply manufacturers, Antec and Thermaltake, to see what they had to say. Antec told us that its tech support reps have "found . . . exactly one other reported case of this happening the past three years." According to Thermaltake, it may be a case of miswiring, which only happens in one out of about every 10,000 PSUs. The Thermaltake rep also recommended using a multimeter to test the PSU beforehand to avoid any problems, however rare, that might crop up.


At least the motherboard itself wasn't irreparably damaged. The system was able to boot before and during the incident—and it worked without any noticeable problem once the smoke had finally cleared. (Although, of course, we tested it with the barest-bones setup we thought we could get away with.) And, thankfully, though those two SATA data jacks on the motherboard are gone, the other four work, so the board is still usable. Just a bit more... charred than it was last week at this time.

Check out the slideshow for photos of the wreckage. Have you had incinerated any of your PC's components—just by turning on your computer? Send us your photos and stories.