How to repair a quartz movement

Discussion in 'Electric Horology' started by kinsler33, Aug 5, 2015.

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  1. kinsler33

    kinsler33 Registered User

    Aug 17, 2014
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    Lancaster, Ohio, USA
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    The situation is that clocks with battery-quartz movements have been sold for close to thirty years already and a good many folks attach considerable sentimental value to them. And while the usual repair procedure is to just replace the movement, sometimes a reasonable replacement isn't available.

    And so I try repairing the things. The latest one is a Bulova miniature brass tambour dresser clock with an alarm. The alarm works, but the movement is dead, probably due to a bad integrated circuit which is also unavailable. The motor coil seemed okay: it had a resistance of something like 475 ohms, but it wasn't receiving any current.

    After more thought and investigation than it should have taken, I tore apart another quartz movement (they're about three bucks from Timesavers) and extracted its electronics board. This is a tiny thing containing the crystal and a lump of black epoxy glue within which lurks the integrated circuit. There are positive and negative 1.5 volt power terminals (marked) and the motor coil is connected across another pair of terminals.

    I soldered the motor coil leads to these terminals (after de-soldering the donor movement's coil from the board) and ran leads from the Bulova's AA battery holder to the power terminals of the tiny circuit board. Behold: the Bulova movement began ticking, and the alarm seems to work, too.

    There was enough extra room inside the Bulova's case to accommodate the extra circuit board and connecting wires, and it's ticking away merrily.

    Mark Kinsler

    and I didn't have to polish the pivots

    Lancaster, Ohio, USA
     
  2. Rob P.

    Rob P. Registered User

    Dec 19, 2011
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    Re: Reparing a quartz movement

    Oh you cheater!

    Get back in there and polish those pivots or we'll report you to the solder fairy.
     
  3. bangster

    bangster Moderator
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    Jan 1, 2005
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    Re: Reparing a quartz movement

    Kool! :coolsign:
     
  4. Tinker Dwight

    Tinker Dwight Registered User

    Oct 11, 2010
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    Re: Reparing a quartz movement

    It makes one wonder if there is a market for a simple
    module that would include the chip and crystal that
    could be easily substituted for these parts on the boards?
    Tinker Dwight
     
  5. dAz57

    dAz57 Registered User

    Dec 7, 2011
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    Re: Reparing a quartz movement

    I have plenty of modules, seeing I hardly chuck anything away I have boxes of old movements, this is great for the BQ movements for spare parts, the quartz of the latest generation seem to last 5 to 10 years, most of them die from leaking batteries, or the mechanicals gum up, with most the circuit is fine,

    when I come across a clock with a quartz movement only made for that clock, like a tide function, alarm, world time dial etc, I clean the movement and use a circuit out of a scraped movement, the circuit is small enough to fit inside the older movement case, and I have taken clippers to the board to make it smaller if I have to.

    Customers are quite happy to have their clock working the way it's supposed to instead of being told to throw the clock away or the special functions will no longer work because of the stock movement that replaced the original.
     

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