Hour and minute hand stops but seconds keep sweeping away?

[horologist]

My only genuine eta that I had serviced professionally before I began attempting them myself has just pulled a strange stunt!  It stopped at 4.23 On Saturday pm, but the seconds hand keeps sweeping away!  Pulled out he crown to see if it could have been a problem with motion work Such as the hour wheel and minute wheel But all seemed good as I could move all the hands over the 12 hour revolution!  Yesterday it stopped again and considered doing a thorough investigation by removing dial and seeing the hour and minute wheel etc to see if all the teeth are ok and all seemed to be meshing well!  Cased it all up again and same problem!  Anyone had a similar experience???

please throw in your theories,  was thinking of replacing it with a clone as that is all that is available at an affordable price! Argggggggg what did I say??   No fear!  
thanks guys!!

[alligoat]

Sounds like you're missing a tooth on one of the gears- could it be the fourth wheel?

[horologist]

22 hours ago, alligoat said:

Sounds like you're missing a tooth on one of the gears- could it be the fourth wheel?

thanks for your input!  They were the first parts I looked at when I stripped it apart which is why I am finding it a mystery!  The other thing I could possibly brainstorm is the tension on calander works!  Just clutching my straws!

[automatico]

Check the canon pinion and see if it came apart (outer wheel came loose from minute hand tube) or is too loose to have enough friction to drive the time train.  Later ETAs have a CP that is simple and rugged but when they wear out or come apart the symptom you described is what happens.  Usually the time stalls when it gets close to changing the date or when the date flipper works starts to load up.  The SS hand will continue to run with a loose CP.

 

If the movement does not have a 'keeper plate' holding the CP in mesh the CP can come out of mesh.  A dial washer will usually fix this.

 

If you set the time ahead a few hours and it keeps time for a while the CP is usually the problem.  Another check is to see if there is much resistance when setting the time...if the crown turns very easily it is an indication that there is not much CP friction.  Check the friction with the movement out of the case or with a long stem so the crown gasket is not supplying friction on the case tube.

 

If this is the problem a new CP is the best fix.  I never had much luck refitting or tightening them.  The 218 Accutron has a similar CP and you can flip the outer drive wheel over and remount it and it will be as good as new.  The ETA is similar but this fix does not work very well.

[horologist]

On 7/23/2020 at 2:59 AM, automatico said:

Check the canon pinion and see if it came apart (outer wheel came loose from minute hand tube) or is too loose to have enough friction to drive the time train.  Later ETAs have a CP that is simple and rugged but when they wear out or come apart the symptom you described is what happens.  Usually the time stalls when it gets close to changing the date or when the date flipper works starts to load up.  The SS hand will continue to run with a loose CP.

 

If the movement does not have a 'keeper plate' holding the CP in mesh the CP can come out of mesh.  A dial washer will usually fix this.

 

If you set the time ahead a few hours and it keeps time for a while the CP is usually the problem.  Another check is to see if there is much resistance when setting the time...if the crown turns very easily it is an indication that there is not much CP friction.  Check the friction with the movement out of the case or with a long stem so the crown gasket is not supplying friction on the case tube.

 

If this is the problem a new CP is the best fix.  I never had much luck refitting or tightening them.  The 218 Accutron has a similar CP and you can flip the outer drive wheel over and remount it and it will be as good as new.  The ETA is similar but this fix does not work very well.

Thanks R.

I have never experienced this issue before with any of my previous timepieces!   Definitely gives me new insight to a different diagnosis to what I had been contemplating!   I checked the the turning of the crown and it seemed to be half and half so this is a close call!   As for telling the time, it is running well for a few hours until it decides to freeze the hour and minute hand!

 

I have noticed that the day wheel flipper intermediate wheel post seems to be protruding and would go for your suggestion that something in that area is the issue!  Since it does not quick set, there must be something causing a problem from there!  What it is ,I am still clutching my straws.  As for a replacement part issue, then we are back to the NPFU dilemma just like with getting Genuine Rolex Parts