Eta 2671 Strange Problem

[clockboy]

Hi,

I have had a watch (ETA 2671) returned from a customer who says the the watch runs perfect & keeps excellent time apart from when she goes to bed. It seems to stop after approx 7 hrs. This watch had a new counter glance bearing fitted & I also fitted a new mainspring. I just can not find a obvious fault . i have attached the "Timograph" readings the first one is dial up & second dial down. When the dial is down there is a bit going on occasionley I was wondering if this is showing the fault.

If anyone has any ideas what I should look for It will be much appreciated..

 

 

[WillFly]

Whenever I've had trouble with a watch doing silly things in one position, it's often turned out to be a loose or cracked jewel or a damaged balance staff. I once had a pocket watch that worked in every position but dial up. Diagnosis - cracked jewel - which only showed up  when the thing was on its back. Unfortunately I'm not up on Timegrapher readings - no help there from me!

[clockboy]

Thanks Willfly,

I think you might well be right although I normally check the jewels when stripping a watch. Perhaps I have missed this one.

Also it is strange I never spotted this when testing after the clean.

On close inspection I have noticed a small crack on the crystal & if I had spotted this I would have offered to replace it.

Wondering if the customer has dropped it, if so it could be a balance job !!!!!

Edited July 26, 2014 by clockboy

[bobm12]

Just thinking, could the new spring be slipping somehow?

[clockboy]

No I checked that. It is a new spring and the barrel is in very good condition. Willfly is in the right area for certain I am just annoyed that I missed it when servicing. I will have to strip & investigate

[Geo]

You might find some of the information here helpful.

http://www.witschi.com/download/Witschi%20Training%20Course.pdf

[bobm12]

Oh yeah! That's what I'm talking about! Thank you Geo, great pdf!

 

clockboy, sorry you have to strip it again! I hope you find the fault. Sometimes a tiny little thing can spoil long and meticulous hours of work! I know, I just went through a similar situation. Luckily it wasn't for a customer (which means I'm free to curse all I want to get even!) :)

[RosscoInOshawa]

You might find some of the information here helpful.

http://www.witschi.com/download/Witschi%20Training%20Course.pdf

Thanks for sharing Geo, I've been looking for something like this after first reading this and other posts on timegrapher's

[clockboy]

Forgot to follow up with this one.

Stripped the watch again and did not find anything wrong i.e. jewels were Ok. So I cleaned again re-assembled and all is now OK.  I can only presume that it had picked up some gremlin on the balance staff or balance jewel but to be honest I really don,t know other than the customer is happy & so am I.

[clockboy]

I should have added to the above is I have used a water based cleaner in a ultrasonic cleaner for many years and this was the last watch I cleaned with this solution. 

When I re-cleaned I used ELMA cleaning solution and maybe this proves that the cleaner is better who knows !!!!