At 10:57 PM 8/16/01 -0000, you wrote:
>Spehro,
>    It does sound like a "cold" solder/weld joint on the lead.....however,
>I'd like to pass on a bit of "crystal" experiment of my own.  Years ago, I
>bought  a VCR that had a clock that  ran about an hour fast every day.  My
>previous wife said "your an electronics technician, fix it".  Thinking about
>it, I remembered an old electronics project book that had a clock with a
>CD4049 divide by "N" chip and a crystal.  I looked inside and saw two TV
>colorburst crystals.  Sure enough, there was a CD4049 next to one of them. I
>took a screwdriver tip and knocked very hard on the crystal case and put the
>VCR back together.  Sure enough, the clock then worked accurately.  The
>crystal was operating in a second mode of resonance.  I went to work and
>told some other people this story and got alot of skeptical comments from
>one guy.  About 3 months later, same person humbly told me he had worked on
>a similiar VCR with the same problem and that had been the fix.
>Regards,
>Mike

Interesting. I've seen "dead" crystals of poor quality that were actually
shorted to the case. If the case had not been grounded, the crystal might
not have appeared to fail. The manufacturer, I believe, never tested that
aspect of the crystals.

Note here, I'm suggesting that the glass seal is broken, so that when the
crystal case is moved it's actually yanking the crystal (something like
a disk usually) back and forth inside the metal case. If you cut open an
old crystal, you'll see what I mean.

Best regards,
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Spehro Pefhany --"it's the network..."            "The Journey is the reward"
speff@interlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com
Contributions invited->The AVR-gcc FAQ is at: http://www.bluecollarlinux.com
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