Jump to content

Longines moon phase chronograph balance wheel stopped


Recommended Posts

Hello all

i have a Longines Moonphase chronograph that is less than a few years old and the balance wheel has stopped. Before sending it in for repair, I wanted to ask if anyone had ideas about the problem. The crown on this watch is small, has three positions and can be finicky( hard to move) when moving between positions. Anything to check before boxing it up to the dealer?  Also does anyone know if this is a snap back?

thank you!

Link to comment
Share on other sites

Dose it run any when you shake the watch or advance the hands?     if so , I put the crown in set position, shake to get the oscilator running and advance the hand when running, see if that makes its run as long as you keep pressure on advancing the hands.

Try giving it a full manual wind, listening close you might here a sound of sudden power discarge from the barrel.

Dose it make a difference weather in chrono mode or not? 

Regs

 

  • Thanks 1
Link to comment
Share on other sites

If it's the one I'm thinking of it's likely a snap back. As this is a 7751 base (with column wheel), my first guess would be a screw came loose and is blocking the movement. The 7750 calibers are known for working the movement screws loose if they aren't tightened to 80ft/lbs.

  • Thanks 1
Link to comment
Share on other sites

40 minutes ago, Nucejoe said:

Dose it run any when you shake the watch or advance the hands?     if so , I put the crown in set position, shake to get the oscilator running and advance the hand when running, see if that makes its run as long as you keep pressure on advancing the hands.

Try giving it a full manual wind, listening close you might here a sound of sudden power discarge from the barrel.

Dose it make a difference weather in chrono mode or not? 

Regs

 

Thanks Joe

My guess is there is a malfunction in the keyless works. Obviously there is a crown position that stops the rotor and it seems to be stuck in that position. No amount of watch movement makes the rotor move.

here are a few pics though not sure how helpful they would be in this problem. The display back looks like it is a snap type but seems unusual for this watch.

D0CEA3BE-20F3-4360-8627-027860190421.jpeg

C96AC3CD-76D4-4939-81FC-EE9ECE777D8F.jpeg

50DE1B00-985A-4F0D-8449-ACD12BBF52EF.jpeg

Link to comment
Share on other sites

9 minutes ago, cduke said:

Thanks Joe

My guess is there is a malfunction in the keyless works. Obviously there is a crown position that stops the rotor and it seems to be stuck in that position. No amount of watch movement makes the rotor move.

Did you mean to say " there is a crown position that stops the oscilator( hack feature) ".

   No crown position should stop the Rotor.

I agree it sure sounds like  the problem is in the keyless, perhaps stuck in hack position. 

 

  • Like 1
Link to comment
Share on other sites

28 minutes ago, nickelsilver said:

If it's the one I'm thinking of it's likely a snap back. As this is a 7751 base (with column wheel), my first guess would be a screw came loose and is blocking the movement. The 7750 calibers are known for working the movement screws loose if they aren't tightened to 80ft/lbs.

Yes I have heard of this before. I was hesitant to open it up but perhaps I can inspect the rotor through the display back. 
this is a likely scenario as I have read online.  If the crown weren’t difficult to maneuver I would dismiss the other scenario.

Link to comment
Share on other sites

The hack on these can get out of sorts, but it's pretty rare. But can happen. So that's a possibility. But I've worked on them ex-factory service where 9 out of 10 screws were loose, to the point it was comical except that the customer wasted their money on the factory service.

Link to comment
Share on other sites

4 minutes ago, Nucejoe said:

Did you mean to say " there is a crown position that stops the oscilator( hack feature) ".

   No crown position should stop the Rotor.

I agree it sure sounds like  the problem is in the keyless, perhaps stuck in hack position. 

 

Yes that is what I meant to say. But the balance wheel does not move at all.

Link to comment
Share on other sites

1 minute ago, nickelsilver said:

The hack on these can get out of sorts, but it's pretty rare. But can happen. So that's a possibility. But I've worked on them ex-factory service where 9 out of 10 screws were loose, to the point it was comical except that the customer wasted their money on the factory service.

Display back looks like a snap back to you?

Link to comment
Share on other sites

3 minutes ago, Jon said:

I've got a 7750 with exactly that problem... the stop lever has got jammed against the balance. You can just see it when you look at the balance from the side

Have you fixed it? The complications on this watch movement are serious to me.

Link to comment
Share on other sites

4 minutes ago, cduke said:

Have you fixed it? The complications on this watch movement are serious to me.

Not yet... just took a pic to show. I highlighted the jammed stop lever with a red circle. The keyless work is pretty jammed up as the stop lever has also got caught in the clutch, I believe.

Inkedstop lever_LI.jpg

Link to comment
Share on other sites

3 minutes ago, Jon said:

Not yet... just took a pic to show. I highlighted the jammed stop lever with a red circle. The keyless work is pretty jammed up as the stop lever has also got caught in the clutch, I believe.

Inkedstop lever_LI.jpg

Thanks Jon. Good luck with it.  I thought my watch and I just had a screw loose in common.?

  • Haha 1
Link to comment
Share on other sites

2 minutes ago, cduke said:

Thanks Jon. Good luck with it.  I thought my watch and I just had a screw loose in common.?

Thanks.... lol

It could very well be a loose screw. Here's a pic of an Oyster Perpetual I worked on recently with a bridge screw jamming up the escape wheel. As @nickelsilversaid, it's almost comical... Almost!

InkedDSC_0037_LI.jpg

  • Thanks 1
Link to comment
Share on other sites

6 minutes ago, Jon said:

Thanks.... lol

It could very well be a loose screw. Here's a pic of an Oyster Perpetual I worked on recently with a bridge screw jamming up the escape wheel. As @nickelsilversaid, it's almost comical... Almost!

InkedDSC_0037_LI.jpg

Thanks Jon. I appreciate everyone’s help and will post what I find tonight. Great pictures too!

  • Thanks 1
Link to comment
Share on other sites

8 hours ago, cduke said:

Thanks Jon. I appreciate everyone’s help and will post what I find tonight. Great pictures too!

Ok, opened the back, balance wheel pivots freely, watch is fully wound, as balance wheel pivots, pallet fork does not advance escapement wheel.  This is apparently the symptom of the problem. On the good side, no loose screw.

Link to comment
Share on other sites

13 minutes ago, cduke said:

Ok, opened the back, balance wheel pivots freely, watch is fully wound, as balance wheel pivots, pallet fork does not advance escapement wheel.  This is apparently the symptom of the problem. On the good side, no loose screw.

The pallet fork appears to move and I can only see one pallet jewel which seems fine, the other jewel is obscured by a bridge on top of it. This movement is dense.

Link to comment
Share on other sites

26 minutes ago, cduke said:

The pallet fork appears to move and I can only see one pallet jewel which seems fine, the other jewel is obscured by a bridge on top of it. This movement is dense.

It appears as though the balance wheel stud is no properly engaged in the pallet fork. Also the jewels are not synced properly with the escarpment wheel.

only a novice observation....

Link to comment
Share on other sites

4 hours ago, Klassiker said:

If you are planning to send it for a dealership service anyway, now would be a good time to box it up and send it. There appears to be something broken, which you will not be able to fix. Better safe than sorry.

Good advice. Thanks

Link to comment
Share on other sites

  • 2 weeks later...
On 4/1/2021 at 8:21 AM, nickelsilver said:

The hack on these can get out of sorts, but it's pretty rare. But can happen. So that's a possibility. But I've worked on them ex-factory service where 9 out of 10 screws were loose, to the point it was comical except that the customer wasted their money on the factory service.

I waited for two weeks for Longines to send service box. Finally, thought to give it a try, popped off the back, removed balance assembly, removed pivot fork and found a big case screw stuck up in the escapement wheel. Removed it, put it all back and it is now running as well as before. Best thing about advice, good to take some and not other.  Thanks again for all the good advice!

  • Like 2
Link to comment
Share on other sites



  • Recently Browsing

    • No registered users viewing this page.
  • Topics

  • Posts

    • yes I noticed the new site and I miss the old site. It's the unfortunate problem of the Internet here today gone tomorrow sometimes some of the stuff gets backed up and sometimes well it does not then the problem with the early Seiko's were there were not necessarily designed for distribution across the planet and as such there is no customer support for them. So trying to find early stuff like technical information or sometimes even parts list for older Seiko is is problematic. But I did find you a you tube video. A quick look he seems to take a heck of a lot of time to actually get to the service single I did not watch all that but it does look like he did disassemble or started to say there's a tiny bit here  
    • RichardHarris123: Hello and welcome from Leeds, England.  I have family all over Australia, went as £10 poms Thanks Richard. Hope you’re able to visit your family here and that they’ve all done well 🙂 My relatives arrived from England in the 1790s transported on the ‘Second & Third Fleets’—a story of timber sailing ships, of convicts and doing well in this huge Country of Australia. When I visited the UK in the 1980s, I was too young to comprehend the depth and breadth of its history…  Best wishes, Mike William Chapman, my 4th great Grandad’s charges, at age 23 read at the Old Bailey; sentenced to 7 years of transportation to Sydney.
    • The whole process and the progress are closely observed, it's hand-driven and very controlled. I can't see the "danger", unless you are watching the TV while doing it. As you could have read, and in this quote "wheel" is the balance-wheel.
    • Have you got the pallet fork installed in the movement when you see the train move when using the setting works? As nevenbekriev said, without the pallet fork to lock the train, the behaviour you are describing is normal. If this is happening with the pallet fork installed, you have a problem in the gear train, it should be immobile when the pallet fork is locking the escape wheel.  The fit of the circlip above the pinions on that wheel is crooked in your pictures, it should sit flat up against the upper pinion as in Marc’s picture.  Hope that helps, Mark
    • Hi I got a Jaeger LeCoultre K911 movement, where one of the stems was broken. Part no. Should be 401.  Im based in Europe and tried Cousins but its discontinued. They except to get stem in stock for cal. K916 but will that work? Or Is there a way out to join the ends?
×
×
  • Create New...