Apr 14 2012

Short Circuits: Adventures in Practical Electronics; or,
The Curious Case of the Valetudinarian Digital SLR

Digital SLRs don’t often give trouble, but when they do, the ailment is often intractable. Since so much depends on the camera’s electronic brain, diagnosing problems can be all but impossible for anyone who isn’t an engineer, and the fix frequently involves the digital equivalent of brain surgery. Luckily, my Pentax K200D has performed flawlessly throughout its three-year life span. Until last week, that is. Here’s what happened:

I was putting my new Raynox DCR-150 lens through its paces, shooting picture after picture from a tripod, using a cable shutter release. For the first 59 shots, all went well, but on the 60th shot I didn’t hear the muted “clunk” that signals the mirror’s return, and when I then attempted to review the image, the LCD display remained dark. Were the batteries dead? That was my first thought. But it was quickly dispelled by the camera’s little status panel. This showed the batteries still at full charge.

By now I’d begun to doubt that I’d heard anything out of the ordinary. I even questioned whether I’d actually snapped the shutter. So I pressed it again. Nothing happened. Only then did I think to look though the optical viewfinder, confirming that the mirror was indeed locked up. It seemed I hadn’t been hearing things, after all. Reasoning that my camera might be as confused as I was, I gave it a brief time-out, shutting it off for ten seconds or so before powering it up again. Such “rebooting” occasionally helps an addled digital camera recover its wits. Now, however, it seemed to make things worse. My camera immediately snapped a shot entirely on its own, though no image subsequently appeared in the display. Once again, the LCD remained black, a state which no amount of button-pressing could dispel. And repeating the power down–power up routine gave exactly the same results.

I was running out of options, and anyway, I’d had enough. I shut off the power and removed the batteries, then I left the camera to its own dark devices for a good five minutes before putting the batteries back. This time around the indicator in the status panel did not show the batteries to be fully charged. Instead, it blinked continuously, signaling that they were critically depleted and lending support to my early suspicions. Well, I had nothing to lose by replacing the batteries with a fresh set, and that’s exactly what I did. It was the work of only a minute to pop my reserve Eneloops into the camera—and pop their rundown predecessors into the charger. Then I went back to shooting pictures.

The result? My camera now functioned normally. And what did I conclude from this? That my rapid-fire shots were too much for the battery indicator in the status panel. It was simply too slow to respond, allowing the batteries to become so depleted that normal operation was impossible. There wasn’t even enough juice left to update the display. But once I removed the batteries, even for a short time, they recovered just enough to correct the status display and permit a proper shutdown. Once that was accomplished, installing fresh batteries completed the cure.

 

Lessons Learned

In future, if my digital camera starts to exhibit erratic behavior, I won’t rely on the battery status indicator’s reassuring message that the juice is flowing normally. Instead, I’ll assume that the indicator is leading me astray, and I’ll power my camera down. Then I’ll replace the batteries (or battery, if the camera in question uses a proprietary power pack). If all is well after that, I’ll have fixed the problem. And if it’s not? At least I’ll have done nothing to make things worse. But then it will be time to start looking around for a digital brain surgeon.

Full Charge Ahead



Further Reading

 

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