02.16.06
Self-Repairing Electronics
When I worked in tech support, we had a name for the phenomenon of problems that mysteriously resolve themselves as soon as a tech arrives to help: “Solved by Tech Proximity.” It happens a lot—either the problem was transitory to begin with, or the process of walking through the symptoms makes a user more careful and conscious of the correct procedure, so he doesn’t make whatever mistake he was making when the tech wasn’t there. But since I am the tech guy, it’s not supposed to happen to me.
Here’s what I’m talking about:
- I bought a car power adaptor for my aging, battery-challenged iPod. When plugged into this adaptor, my iPod emitted a hissing sound through the headphone cable that leads to my auxiliary input adaptor. I spotted what looked like a line-out jack on the power adaptor and tried plugging the auxiliary input cable into that. With a loud pop! the auxiliary input adaptor stopped working. Turns out that jack was intended to supply power to an FM transmitter.
- After a period of rest, the auxiliary input adaptor worked again, but poorly. The sound was tinny and I really had to crank the volume on the head unit to hear it, making switching between iPod and radio a pain. Also, the display on the head unit went blank when I switched to the iPod, and I couldn’t switch between the auxiliary input adaptor’s two input channels.
- Shortly after all this, my PowerBook’s internal hard drive stopped working—it wouldn’t even spin up. I had a recent backup on an external firewire drive, and my PowerBook automatically detected that and booted from it, but this made synchronizing my iPod difficult because the iPod doesn’t like FireWire daisy-chaining—it likes to be the only FireWire device present. But if I held it just right (for some reason it seemed to work better if the cable was perfectly straight—lack of cable shielding, maybe?) it worked—slowly.
- I figured I’d kill two birds with one iPod car charger. This particular model comes with a USB docking cable that plugs into the charger, so I figured not only could I power the iPod in the car, but when I got home I’d take the cable in and sync to iTunes with it. But it turns out my iPod is too old for this to work—it syncs via USB, but it won’t derive power from it.
- Not knowing this, I plugged the charger into my cigarette lighter, the cable into the charger, and the iPod into the cable. There was another pop!—and then unusually loud music. My adaptor was working normally again—it sounded great, the display on the head unit worked, and I could once again switch between inputs.
- When I got home I took the USB cable in, figuring that part of the plan was still worth a try. There was a message on my computer screen (which I’d left on all day, downloading via Bittorrent) saying the computer needed to be rebooted. When I did that, one of the partitions on the external drive failed to show up. This was annoying, but then I noticed that the computer had booted from its internal drive rather than the FireWire drive. SMART diagnostics found no problem with the internal drive, and the bad partition on the external drive had minor directory problems from which I didn’t even bother recovering the data, since I no longer needed it anyway.
Self-reparing electronics: really cool, or kinda creepy? I say cool.
