Help with chrono hand issues

Posts
2
Likes
0
This is more of a general question. I've recently picked up a few older speedmaster dates and seamaster chronos.

3 of 5 I've dealt with have had issues with the chrono hands resetting to 12. I've used good sites for the purchases and have been able to send them back after trying to negotiate with the sellers.

How common is the issue?

It seems to impact the hour hand the most.
Any guides of repairs or other fixes outside of sending to omega? I don't have any good indy repair shops locally so either need to learn to work on them or send it off. Any DIY check or simple ways I could look at the movement to identify an issue or does it require a full service?

Thanks!
 
Posts
29,877
Likes
77,289
Are these ETA/Valjoux 7750 based?
 
Posts
29,877
Likes
77,289
If it is not resetting exactly to zero there are two different ways it can do that.

One is that when you press the reset it just never hits the zero. This is most likely due to incorrect hand installation, so someone didn’t install the hand right on zero.

The other is that when you press and hold in the reset button, the hand is on zero, but when you release that button the hand moves off the zero position.

For the first the only solution is to remove and install the hand properly.

For the second this can be caused by magnetism between the hammer and cam of the wheel, or possibly by excess oil or gummy oil. You can try to demagnetize the watch and if that doesn’t work, then it needs a service.

So this is mostly not something you can solve by yourself…
 
Posts
90
Likes
20
Chronograph movements are not simple and some regulations can damage the movement.
takes ages to learn and £ for equipment
Best option would be a watchmaker in our days most services accepts postage and rates are visible in google or trustpilot utt
7750 is simple movement so is not necessary to send it to Omega places as most watchmakers got skills so you will save a large amount


I would advice you to learn simply things such as hands re set ( you would need special stands )
some type of oiling , bracelet stretch.. possibly glass change this would be a great start for you