Scavenging

The Ghost in the Machine

One of the creators of this blog (and one of the coauthors of The Scavengers’ Manifesto) likes to drag home broken electronic items — not just to pry them apart and see what’s wrong, but to understand on a physical level why each piece of equipment was made this way in the first place. Here’s his account of one such incident:

A few years back, I found an old early 1960s-era hi-fi stereo receiver in a Dumpster; unable to resist, he lugged it ten blocks to my house. As expected, when he plugged it in and attached it to his speakers and turntable, it didn’t work. The lights came on but no sound came out. So he unplugged everything, took it apart, and looked at the dysfunctional innards. As he puts it:

Now, I am no electrician. I do not have an engineering degree. I’ve never worked at a stereo component store, and I have no formal training in electronics. (Or informal training, for that matter.) But I knew that this stereo must have originally worked, and now didn’t; something had changed, something was wrong, and I felt I ought to be able to figure out what.

So I looked. I peered. I observed. I spent minutes, then hours, following wires from one side of the cabinet though labyrinthine connections to the other. I sniffed at fuses and welds to see if they smelled burned. I took out a magnifying glass and looked for tiny scorch marks that might indicate a bad connection. I tried to grok the entirety of how this machine was designed. If I push this button, then that closes the switch over here, which then sends a signal down this wire, which connects to this mysterious metal box; from there a yellow wire goes to this light and a blue wire connects to this other button….

I felt like I was having a conversation with the bespectacled hi-fi geek in the design department of a 1961 record-player company. Little by little I eliminated areas and systems and wires that couldn’t possibly be the problem. My ghostly mentor with thick lenses gazing over my shoulder, shaking his head in disapproval whenever I overlooked something, nodded in satisfaction whenever I grasped a subtle design point. So that’s why the fuse has to be between the capacitor and the power cord!

After four hours of this obsessive-compulsive hands-on reverse-engineering lesson, I had narrowed the problem down to a single green primitive integrated circuit board; the flaw was to be found there, I was sure of it. Not because I knew what the flaw was, but because it simply couldn’t be anywhere else. But the board looked perfectly intact; the connections seemed solid, nothing looked burned or melted. So I took out a flashlight and my strongest magnifying glass and inspected it inch by inch. And there, almost invisible, I saw it: a tiny metallic filament of what I later determined to be Christmas tree tinsel, which had apparently fluttered through the air vent on the stereo one long-ago winter day, landed across two pathways on the board, and created a short-circuit at a fatally crucial juncture. My suspicion was that the short-circuit was at first only intermittent or flickering, as the tinsel was still motile. But at some point — 1966? 1971? Who knows? — a combination of cigarette smoke and dust and moisture had essentially glued the tinsel in place, and the short circuit became permanent. The stereo stopped working, so it was put in a garage. And when Dad moved to the retirement condo, it went into the Dumpster.

In the end it was so simple: I took a pair of tweezers and carefully dislodged and lifted out the quarter-inch bit of sticky tinsel. I somehow knew, even before putting the whole thing back together and plugging it back in, that I had fixed it. And I was right. I pressed the On button and glorious stereophonic hi-fidelity music filled the room. And I could feel the presence of the previous owner and the manufacturer and the designer and everyone back to Michael Faraday and Alessandro Volta standing there with me, smiling.

That is the secret joy of scavenging.