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6139-6015 Issue/Maybe not?


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Hi guys back again.

Thanks for all the help you all provided when I was troubleshooting the bulova, it is running amazing now.

I have a 6139 Chrono that looks great on the timegrapher.  It is running at +8 s/d and 0.1ms beat error, it keeps awesome time when I am wearing it, but for some reason when I leave it in my watch box overnight it seems to lose a couple of minutes.  The hands dont seem super loose or anything so the only thing I can think is the calendar works slows it down when its switch day/date?

Any thoughts or help would be greatly appreciated.

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Advance the hands by 12hrs, compare time on the watch with time on your smart phone or a reliable time piece, between 10am to 2pm, you should notice if it slows down in this 4hrs time period. 

How long is it actual power reserve?

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2 hours ago, Wdschell said:

for some reason when I leave it in my watch box overnight it seems to lose a couple of minutes. 

Try different resting positions, finding them either with the help of a timegrapher, or just with patience over days. 

This ancient method of averaging errors is nowadays almost forgotten by many watch owners expecting quartz like accuracy from their mechanical pieces, no matter their make, vintage or conditions. 

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39 minutes ago, Wdschell said:

I would guess around 30ish hours.  I haven't actually checked it, but it seems to run 24ish hours after I am done wearing it before it stops completely.

Also did you mean 10pm to 2am when it starts to change the date/day?

The power reserve is acceptable.

I meant advancing hands by 12 hrs , then it changes date at noon ,so you have a chance to observe time on it and compare with a reliabke time keeper.   Otherwise as jgm says , its likely to depend on its resting position. Face up or down etc.

Regs 

joe

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10 hours ago, Wdschell said:

I'll run that test tomorrow.  If it is running slow during that time period would that indicate a problem of some sort?

It would show the jumper mech is heavy footed, .if it slows down only when trying to jump the day/ date, we can conclude jumping is what slows the rate.

When servicing the movement, one would have a chance to make such observation without and with the date mech engaged.

A clean and new lube on date complication might improve things.

Regs 

Joe

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3 hours ago, Melt said:

I would check the plastic day date wheel for bent teeth or a bent finger.

 

Ya, plastic jumpers, actually any faulty parts in day/ date complication, bent day disk for instance or simply dried out grease in disk groove. Spotting the fault now can get to be a pain.

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When I serviced my 6139B the date finger (868611) and Intermediate date wheel (81760) were both made of plastic and had some damage.  I replaced both of them with new (from schillachi61 on ebay, a great source for seiko parts).  The new intermediate date wheel was now metal.

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Ok, I will take this chance to practice my fault finding.

Thanks canthus I will check those pieces out when I have it apart.  Thanks for the seller to I wasn't sure whether to order parts or to order a whole parts movement if some sort

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