7751 fault: Comments?

[markrlondon]

I've just taken delivery of a Glycine Ningaloo Reef Compliqué with a 7751 movement. Everything works fine except one thing: The moon phase dial does not advance when the watch is manually wound on. All the other complications advance as expected. I've not had it long enough to see if the moon phase advances if the watch is left to tell the time normally but I doubt it. The moon phase can be set as normal using the crown as can all the other complications.

Any thoughts on this? It sounds like it should be an easy fix but I just wondered if anyone could provide any insight into it.

[744ER]

I've just taken delivery of a Glycine Ningaloo Reef Compliqué with a 7751 movement. Everything works fine except one thing: The moon phase dial does not advance when the watch is manually wound on. All the other complications advance as expected. I've not had it long enough to see if the moon phase advances if the watch is left to tell the time normally but I doubt it. The moon phase can be set as normal using the crown as can all the other complications.

Any thoughts on this? It sounds like it should be an easy fix but I just wondered if anyone could provide any insight into it.

Are you sure it doesnt move? Its quite a small movement, coupled with a yoke going to the daywheel. If not then something is up with the yoke and the spring there, possibly damaged or oils dry, spring not where it should be... Impossible to guess really.

Dial and all the hands need to come off and back on etc so its not the smallest of jobs, it can be a little finicky if not used to it :)

[markrlondon]

Are you sure it doesnt move? Its quite a small movement

Yup, it definitely does not move. I wound the watch on for several days such that movement of the moon phase wheel should have been obvious and there was definitely no movement. Also, movement of the wheel is clearly visible when correcting the moon phase individually via the crown so I know I would be able to see it if it was moving as it should be when winding the entire mechanism on.

coupled with a yoke going to the daywheel. If not then something is up with the yoke and the spring there, possibly damaged or oils dry, spring not where it should be... Impossible to guess really.

Thank you very much indeed for this. It is most informative!

From looking at that picture I can appreciate that it could be, as you say, anything up to and including the yoke being entirely missing.

Dial and all the hands need to come off and back on etc so its not the smallest of jobs, it can be a little finicky if not used to it :)

Quite! It's certainly not something I intend to attempt myself. This will be going to a competent watchmaker, but I nevertheless still wanted to try and gain some insight into what might be wrong and you have provided it. Thank you.

[markrlondon]

If I may please impose upon your expertise to ask a couple of questions about this mechanism:

1) I presume that the moon phase yoke is mounted on a pivot under the plate and that a cam or finger on the calendar wheel causes it to swivel and thus engage with the moon phase wheel to move it on. Is that correct?

2) The moon phase corrector is actuated by the date/moon phase corrector star when manually correcting the moon phase via the crown?

3) What does the moon phase jumper do?

[744ER]

1) I presume that the moon phase yoke is mounted on a pivot under the plate and that a cam or finger on the calendar wheel causes it to swivel and thus engage with the moon phase wheel to move it on. Is that correct?

2) The moon phase corrector is actuated by the date/moon phase corrector star when manually correcting the moon phase via the crown?

3) What does the moon phase jumper do?

Hi, I had to jog my memory a bit,

Theres an intermediate wheel with a cam and a finger that controls both day-wheel on one level and activates yoke on another (green arrow calendar wheel in the pic).

2. correct, and theres an excenter that has to be carefully adjusted so the corrector hits the moon-wheel-teeth in the exact right spot.

3. Jumper keeps the wheel in place whenever the wheel is not in motion, its a click, so to speak.

See here on page 32: https://secure.eta.ch/CSP/DesktopMod...859&DocType=DT

The probable culprit is the yoke spring, but as I said, could be other causes. All these parts need oil to work perfectly, very small forces at play so a dry yoke pivot could prove harmful for instance.

[markrlondon]

Hi, I had to jog my memory a bit,

Theres an intermediate wheel with a cam and a finger that controls both day-wheel on one level and activates yoke on another (green arrow calendar wheel in the pic).

2. correct, and theres an excenter that has to be carefully adjusted so the corrector hits the moon-wheel-teeth in the exact right spot.

3. Jumper keeps the wheel in place whenever the wheel is not in motion, its a click, so to speak.

[...]

The probable culprit is the yoke spring, but as I said, could be other causes. All these parts need oil to work perfectly, very small forces at play so a dry yoke pivot could prove harmful for instance.

Thank you very much indeed. This is all extremely helpful.

See here on page 32: https://secure.eta.ch/CSP/DesktopMod...859&DocType=DT

Unfortunately this is Access Denied for me. It seems you need to log in as an ETA customer to gain access to the Support Center Portal/Customer Service Portal and I definitely don't qualify.

No matter, as your description has explained to me what I felt I needed to know.

Thanks once again.

[swanbourne]

Don't you set the moonphase via a pusher on the side of the watch?

Eddie

[markrlondon]

Don't you set the moonphase via a pusher on the side of the watch?

The moon phase is set by pulling the crown out to the first stop and turning it clockwise. Turning the crown anti-clockwise at the first stop advances the date hand and month wheel.

Pulling the crown out to the second stop hacks the movement and allows the time to be set.

There is a recessed pusher at 10 that advances the day wheel.

[Kingstepper]

See this http://www.awci.com/wp-content/uploa...I/ETA-7750.pdf

[markrlondon]

See this http://www.awci.com/wp-content/uploa...I/ETA-7750.pdf

Thanks.

[744ER]

Thank you very much indeed. This is all extremely helpful.



Unfortunately this is Access Denied for me. It seems you need to log in as an ETA customer to gain access to the Support Center Portal/Customer Service Portal and I definitely don't qualify.

No matter, as your description has explained to me what I felt I needed to know.

Thanks once again.

No worries! It's the stupid ETA site, you can get to the document here: http://eta.ch/index.php?id=7 click support center, then technical documents, choose from the dropdowns, mecaline specialites and 7751, and it should work.

[markrlondon]

Thanks!