Quote:
Originally Posted by stevehertz
Otherwise, it has been proven that poor contact between connectors can lead to a small diode effect - like a cat's whisker - whereby a degree of rectification is taking place. Old, dirty, corroded, nickel plated phono connectors are a good candidate in that respect.
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I once built a TV video receiver unit with the audio amplifier & speaker in an enclosure. One day out of the blue the audio became horribly distorted. The low signal level was taken from the main board with a plug connector, a typical pcb type, to the amplifier module.
It sounded so bad that I though there must certainly be an IC or transistor bias failure or component failure. I got the scope on the low level signal, and it appeared exactly as though the audio signal had been half wave rectified. It turned out that oxidation in the pcb plug connector pins was the cause and a diode had created itself there.
Because it was audio though I could hear this anomaly, but it did make me wonder if it had been another type of circuit, like a logic circuit, it still might have kept apparently working and I'd be none the wiser or perhaps an intermittent fault. Now I treat nearly all my pcb connectors with wd40.