When Gremlins infested your devices and drove you to distraction

[John_DiFool]

Ever had an inexplicable glitch in some mechanical or electronic contrivance that you could not diagnose and fix no matter what you did?

Closest thing for me was my old Honda Civic (which a friend now owns). Every so often it would start overheating out of nowhere. I’d bring it in, the techs would fix it, and I’d drive off, with the problem seemingly fixed. But 6-12 months later the problem would crop up again. I must have “fixed” it close to half-a-dozen times, including a couple of times for my friend (and yes I warned him about it when he bought it from me). He has almost completely overhauled the entire drive/cooling system, so we shall see if the little buggers go back at it again.

[gotpasswords]

I used to have a stereo receiver that was inhabited by a Hum Gremlin. Every so often, the thing would hum loudly.

I took it back to the shop (This is back in the era when you bought a stereo from a stereo shop, and not some giant place that also sells computers and vacuum cleaners.) and the service guys (also from an era when there was an expectation that things could be repaired rather than replaced) could find no problems. Perfectly quiet on their test bench. The guy said they hooked it up and listened to it all day long, and no hums.

Take it back home, plug it in, and hummmm… Back it went. Sure enough, three days later, I pick it up with no fault found. Naturally, it resumed humming the next day.

In frustration, I call the manufacturer, and they refer me to one of their specialists. He knew exactly what the problem was, was able to cause the hum at will, and was able to fix it.

[Mama_Zappa]

Couple of stories of things that baffled us, and the experts (though they don’t entirely meet the OP’s intent as ultimately we solved both of them…)

I posted here, some months back, when my Sony LCD monitor suddenly displayed itself in reverse. As in, right was left and left was right but up was still up, and if I moved the mouse to the right, I could see the little pointer moving left across the screen.

Let me tell you, it was hard as hell to go through all the graphics diagnostics, trying to read the dialog boxes backwards and having my eyes and hands giving me completely different signals. Stumped the computer manufacturer, stumped Sony tech support (who wanted more to repair it than a new one would have cost). Stumped people on tech support boards. Stumped people here.

I actually did solve it myself. I got the wild idea to try hooking the monitor up to my laptop - and sure enough, the display was messed up, which clearly meant the monitor itself was at fault. And we borrowed a monitor to hook up to the desktop, rendering the desktop usable. What finally fixed the LCD monitor though was… unplugging and replugging it. Possibly switching it from analog to digital and back may have helped as well though I don’t know for sure.

There’ve been a couple of other times where it’s gone wonky - everything displayed in a quarter-inch wide bright stripe while the rest is black, or simply blank all over. Every time, the unplug/switch/switch/replug treatment works.

Oh - and the reason we bought that LCD monitor in the first place, 6 years ago:

We bought a used computer from a colleague. Set it up. It locked up after a couple of minutes. Tried it again back at his house. It worked perfectly. Lather, rinse, repeat. We began joking that it was bad feng shui in our house. Then we thought “hmmmm, electrical interference”. We had one of those fake phone connections that allows you to have a phone extension using the house’s wiring (you attach a transmitter to a real phone jack, and a receiver near where you want the phone). We unplugged that… and the computer worked.

We re-arranged things so the computer was on the desktop rather than sitting on the floor… and it quit working again. So we put it back on the floor and it worked again. Looked everywhere and found nothing that could cause the problem. The monitor, an old one which we’d used successfully for years on our still-working old desktop, couldn’t be the problem.

Well, it was. Somehow, the shielding on the new-to-us computer wasn’t as good as on the dinosaur we were replacing, and the monitor was giving off some sort of signals that were getting through to the new-to-us machine. We put the computer back on the floor temporarily, went out and bought a new monitor, put the computer back on the desk… and everything worked perfectly.