Kramer

[Kramer]

Hello from California.  I have an old corum quartz watch that has begun to run very fast , new battery , still fast. Do you think that is repairable?  it's marked corum 247498  and also 956412. I found a 956412 movement that also has numbers dt3/dt6   and    2h/3h . what are the last few numbers referring to ? date3 or 6? mine is at 6  and 2h,3h? thanks anyone, Kramer

[ecodec]

Hi Kramer, I do not know the watch but if it runs that fast Check the frequency the oscillator is running at, 32.768 Khz is the magic figure. You will need a GOOD frequency counter. Look at it at the crystal or the input to the chip.   The timing capacitor may have come adrift etc, from the crystal to the +ve rail. To slow the frequency down you can make up a "gimmick" capacitor and solder it from the crystal  to the +ve rail. Hope this helps.  Regards, Mike.

[oldhippy]

 

Thank you for your introduction and welcome to this friendly forum.

[AndyHull]

Another thing worth checking. Clean the battery contacts on the circuit board. Oxidation of the contacts can vastly increase their resistance which will have a similar effect to a flat battery, as it will reduce the voltage and current available to the circuit. This can cause issues with the oscillator frequency.