WS 6: Repairing a Caliber PUW 910: Replacement Circuit
Here is the old blue and the new black PUW910 Circuit board. I
had learned that blue circuit boards were those manufactured in Switzerland and
Germany and green and black ones pointed to Asian manufacturers. I am not sure
if this is always correct, but it might be helpful in determining whether a
watch still has its original circuit. Also note the PUW logo on the left of the
movement number. Let us have a look at the parts.
Left most, the capacitor that allows to adjust the circuits frequency. In today's movements this regulator is often missing or a lot smaller. The metal tube contains the quartz crystal. I will later add a link here to a page about quartz crystals on Rob B's Hamilton page, quartz crystal manufacturing is often not regarded as important. Today, there are only very few crystal "breeders" on the market that produce high precision quartzes. Of course Seiko and the Swatch Group (ETA) produce their own crystals. I would expect Miyota does the same. The purity of the Silicon Oxide, the shape (there are curved, straight, semi-circular etc. crystals), the tolerance of its dimensions, the "packing" - all are factors that influence a crystals accuracy and life cycle.
Now let us have a look at the underside of the movement.
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