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Posted

Afternoon all,

I’ve been playing around with an old quarts chronograph this afternoon, it is a Miyota cal OS20. After fitting a new battery all seems to be functioning well but the 60 minute counter subdial does not reset to the correct position.

Does anyone have any experience with this movement? Is there anything simple that can be done to fix it?

 

FE190343-0D15-4DDF-BAA7-071472CD9B58.jpeg

Posted

Pull the crown all the way out to the third position (hand setting).

Repeatedly press the top pusher until the chrono sweep seconds hand is at 12.

Press the bottom pusher and the 60 minute subdial should reset to 0.

Push the crown back in.

Posted
13 minutes ago, Marc said:

Pull the crown all the way out to the third position (hand setting).

Repeatedly press the top pusher until the chrono sweep seconds hand is at 12.

Press the bottom pusher and the 60 minute subdial should reset to 0.

Push the crown back in.

 

6 minutes ago, clockboy said:


I suspect it is a re- set issue after changing a battery. See link below.

 

https://miyotamovement.com/downloads/

Thanks gents, I’ve tried both these methods but no luck. The sub-dial still resets to the wrong position......

Any other thoughts?

Posted
3 minutes ago, Marc said:

Have you had the subdial hand off?

 

I haven’t. That doesn’t mean they have been off in the past. Could it be a case of lifting the hand and re-seating it?

Posted
1 minute ago, Robbie010 said:

Could it be a case of lifting the hand and re-seating it?

I think that if the reset procedure outlined above consistently returns the hand to the same (eroneous) position every time then that suggests that the hand has been off and not put back in the right place, in which case yes, just lift the hand and reseat it in the right position.

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Posted

Not a lot of information on the website like a service guide would be really helpful about. But I did snip out a couple of things you'll notice the reset procedure is only for the sweep second hand they don't mention the other hands at all? Then for a clue on the website itself notice the reference to the heart-shaped cams? If they're being truthful about that heart-shaped cams rely on the hands being in very exacting positions otherwise they will not return to where there supposed to be.

https://miyotamovement.com/product/0S20/

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M CR-1.JPG

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