My crappy watchmaker couldn't fix it so I'm gonna do it myself!

[Rolexman]

My v1 Skyland suffers from the same problem as a lot of A7750s. The chrono second and minute hand are not returning straight to zero after reset. A more detailed description of the problem can be foud HERE.

I brought my watch to a local watchmaker and after taking apart the chrono module he told me he couldn't fix it as it had something to do with a loaded spring? This spring was the cause that the hands swung past the upright position before returning to zero (hope this makes sence). Whereas he could alter the torque of this spring on the ETA7750 he couln't on the A7750? Now I really do think I can fix it myself. I already took apart the auto winding module before so I know my way around the movement a bit. I also have a detailled manual so I would like to give it a go.

After closer inspection of the chrono module I noticed the folowing. Take a look at the position of the hammer (photo's can be enhanced by clicking on them).

1. Original reset mode.

2. Chronograph running.

3. Sticking hammer/ chrono cam?

The hammer usually moves in it's original position (picture 1) after I release the reset button but sometimes it sticks (picture 3) and the chrono second and minute hand freeze -sometimes left sometimes right from the 12 o clock marker- in a position other than upright. I have to give the hammer a gentle tap (where the screw driver tip is pointing) to have the hands reset to zero.

Tips and info are much appreciated!

[Rolexman]

No insights? Anyone?

[Francisco]

No insights? Anyone?

Well, probably you have tried this before.

1.- Try to lubricate the bottom part of the hammer.

2.- Try to bend it up. Howeer, this is a bit dangeorus.

Francisco.

[Rolexman]

Well, probably you have tried this before.

1.- Try to lubricate the bottom part of the hammer.

2.- Try to bend it up. Howeer, this is a bit dangeorus.

Francisco.

Thanks Francisco. When you are referring to the bottom part are you referring to A or B? And when you say up would that be bending it towards the dial side or towards the rotor side?

IMO it seems something is jamming at A. Beneath the auto-wind bridge.

Thanks!

[freddy333]

Have you checked to see of the hands are floating (loose) on their tubes? This is a common problem with rep chronograph hands. The joint that is supposed to fix the hand in place on its tube is not crimped tightly enough & the inertia that results when the chrono is reset often causes the hand to stop in different positions every time. Sometimes, it may be off just a bit & sometimes it will come to rest half way around the dial. The fix in these cases is to either recrimp the joint (if you have a staking tool) or cement it with a tiny dab of epoxy (be extremely careful not to allow any of the cement to migrate into the tube or you will be unable to get the hand back onto its pinion)

(Pic credit to Avitt)

[Rolexman]

Have you checked to see of the hands are floating (loose) on their tubes? This is a common problem with rep chronograph hands. The joint that is supposed to fix the hand in place on its tube is not crimped tightly enough & the inertia that results when the chrono is reset often causes the hand to stop in different positions every time. Sometimes, it may be off just a bit & sometimes it will come to rest half way around the dial. The fix in these cases is to either recrimp the joint (if you have a staking tool) or cement it with a tiny dab of epoxy (be extremely careful not to allow any of the cement to migrate into the tube or you will be unable to get the hand back onto its pinion)

Thanks for your reply Freddy. I wish it were the hand tubes. That's an easy fix for me. I tried to describe the problem as good as I can but it is difficult to explain in writing how the chrono hands react when I reset. Even The Zigmeister said he never encountered this phenomenon (see link in post #1). That's just bad look as my last 3 a7750 based reps all suffer from this problem . I would have made a movie of it so everybody can see what I mean, but my camera is of such poor quality it can't even pick up the hands... let alone stand the sweep.

[freddy333]

Thanks for your reply Freddy. I wish it were the hand tubes. That's an easy fix for me. I tried to describe the problem as good as I can but it is difficult to explain in writing how the chrono hands react when I reset. Even Ziggy said he never encountered this phenomenon (see link in post #1). That's just bad look as my last 3 a7750 based reps all suffer from this problem . I would have made a movie of it so everybody can see what I mean, but my camera is of such poor quality it can't even pick up the hands... let alone stand the sweep.

Sorry, none of the pics in your 1st post are showing up here, so I may not have gotten the whole story.

So all 4 of the chrono hands are resetting incorrectly? Are they resetting to the same position each time or different positions?

Is your camera able to do macro pics? If so, can you post a pic showing where the hands are stopping?

By the way, I have had alot of problems with the braking system on a number of A7750s, which cause the hour totalizer hand to continue to run when the chrono is OFF. Does that sound anything like the problem you are experiencing?

Update - For some reason, the link in your OP as well as the pictures did not come up here (using latest Firefox without any blocking on). But I got the link using IE, so I understand the nature of the problem better. From the sound of it, you do not really have a problem. It is just the imprecise nature of these Asian chronos. Some of mine do it as well. As long as the chrono operates & resets correctly (you said it does), I would ignore it.

Sorry about the confusion. I really did read (what I could see) of your OP.

[Rolexman]

So all 4 of the chrono hands are resetting incorrectly?

Nope. They all reset okay. The problem is the way they reset.

Are they resetting to the same position each time or different positions?

Yes, all perfect upwards. So they reset to the correct position.

can you post a pic showing where the hands are stopping?

Yep, will do some tomorow.

By the way, I have had alot of problems with the braking system on a number of A7750s, which cause the hour totalizer hand to continue to run when the chrono is OFF. Does that sound anything like the problem you are experiencing?

Nope, no problem with the braking system.

This is as good as I can describe it:

The new Asian 7750 in my Breitling runs perfect but when I push the reset button (after pushing the 'start/ stop' off course) the second and minutecounter hand of the chronograph jump to 11 respectively 1 o'clock, depending on where they are stopped and reset. When I release the 'reset' button they graduately turn to zero. With the same speed as I release the reset button. The hands don't slip as they always reset to the correct position, pointing perfectly upwards.

[freddy333]

The new Asian 7750 in my Breitling runs perfect but when I push the reset button (after pushing the 'start/ stop' off course) the second and minutecounter hand of the chronograph jump to 11 respectively 1 o'clock, depending on where they are stopped and reset. When I release the 'reset' button they graduately turn to zero. With the same speed as I release the reset button. The hands don't slip as they always reset to the correct position, pointing perfectly upwards.

After I switched browsers, I found the link to your previous post & got the explanation from there. And as others have said, that is the nature of these movements. I find that some of them have more 'play' or 'slop' (imperfect machining/fit) within the components than others. Short of remanufacturing the movement, I am not aware of any way to stop the hand from jumping when reset. The important thing is that it resets correctly.

[Rolexman]

After I switched browsers, I found the link to your previous post & got the explanation from there. And as others have said, that is the nature of these movements. I find that some of them have more 'play' or 'slop' (imperfect machining/fit) within the components than others. Short of remanufacturing the movement, I am not aware of any way to stop the hand from jumping when reset. The important thing is that it resets correctly.

Thanks Freddy. I assume the pics are no longer needed. I will give it a rest.. or sell it to my brother

Your expertise is much appreciated