Jump to content

Valjoux 7750 stopped after stem replacement


Mickeycz

Recommended Posts

Hello,

 

I'm new here and into watch/horology world as well. I recently tried to replace the dial on my 7750 watch.

1) Open the wathc case

2) removed rotor

3) removed stem (gentle push of remove stem pusher and pull the stem out)

4) removed the movement from the case

5) put movment to movement holder

6) removed hands

7) removed dial

8) put new dial

9) pressed the hands back, hovewer during setting it up I realized the movement is not running - even when I wind it up - it is solid/stable and not ticking at all.. 

Kind of out of ideas what can went wrong, the movement was functional correctly before..

 

Thank you for any ideas.

Mickey

 

Link to comment
Share on other sites

hello, I believe I did purchase/replaced the correct stem (bought from cousins uk) - measured it, did visual check before putting it in.  Before removing the stem, put it to the set positon.
 
Thanks for your replies 
Ok. Is the balance swinging. You should be able to wind it as that train is independent.

Sent from my SM-G950U using Tapatalk

Link to comment
Share on other sites

 

9 hours ago, Mickeycz said:

hello, I believe I did purchase/replaced the correct stem (bought from cousins uk) - measured it, did visual check before putting it in.  Before removing the stem, put it to the set positon.

 

Thanks for your replies 

I think the watch is hacked. Does the balance move at all with agitation. If not then then you may have an issue with the hacking mechanism. Even with the hack the watch should still run when stem is removed because your supposed to remove the stem while its seated NOT clicked out in the set position. The stop lever may not be seated correctly with the sliding pinion. Still possible you have the wrong stem, did it state that is for a 7750?

Link to comment
Share on other sites

 
I think the watch is hacked. Does the balance move at all with agitation. If not then then you may have an issue with the hacking mechanism. Even with the hack the watch should still run when stem is removed because your supposed to remove the stem while its seated NOT clicked out in the set position. The stop lever may not be seated correctly with the sliding pinion. Still possible you have the wrong stem, did it state that is for a 7750?
^^^^^^^^what he said.

Some times those stems dont seat when you replace them. If you give it a good tug without depressing the stem release and it pops out there is your issue. I seriously doubt it has anything to do with the hand replacement. Sounds like a botched stem job. Snap a few photos with the crown all the way seated. Id say if the balance is not swinging its probably stuck in the hacked pos.

Sent from my SM-G950U using Tapatalk

Link to comment
Share on other sites

Hello, thank you all for your responses. I wIll make better photos during the weekend as I have kind of time demanding job and watch play is more relax and I don't want to rush much to not make more damage than I already did..

Photos are made by phone and didn't know what to look for - what detail to focus on..

img_1032 - set position

img_1033 - operations position

The stem is correct one - I really did precise check when purchasing and even before putting it in - with magnifying glass and lot of light. 

 

What you mentioned the issue might be that I removed the stem when in "setting position " (as this is what I've read about 2824 stem removal and didn't think for 7750 it is different). 

 

Thank you very much for your help so far.

Mickey

IMG_1033.jpg

IMG_1032.jpg

Link to comment
Share on other sites

hard to tell but it looks like it is hacked.  Technically you can do it in wind or set position with the 2824 but because of issues with the lever slipping off the clutch they suggest doing it with stem in set position so if you are in the "set" camp, you should expect to depress the set lever when re-inserting. If you don't, the stem may move the set lever back into the quickset or wind position...in which case you've defeated the purpose of having it the "set" position to begin with. I prefer stem in wind position esp on movements with hack feature which is standard on 7750 but optional with 2824.

Link to comment
Share on other sites

  • 6 months later...


  • Similar Content

  • Recently Browsing

    • No registered users viewing this page.
  • Topics

  • Posts

    • As with every skill it watchmaking, it takes practice. Notice at the top of the document it says, "Practical work - 40 hours".  I can get the balance wheels 'close enough' to flat, but never seem to get them perfect. Same with gear wheels. Guess I need more practice.
    • Has it got a beat adjustment on the platform or is it a fixed hairspring? in short what you are looking at to get it just about in beat is to get the roller jewel sitting dead centre between the banking pins. So remove the platform and take of the pallet fork and escape wheel to give you clear line of site, sit the platform with the balance in place and with it level look between the banking pins and see if the roller jewel is sitting between them, if it is nice and central its there or there abouts in beat, if its not the the position of the pinned end of the hairspring needs to be adjusted to move the roller jewel into the correct position, thats why I asked if it has an adjustment on the platform or not, if it has its an easier job. 
    • I've managed to adjust it. I'm going to try and explain it as well as I can with my limited horology knowledge but I hope it helps someone in the future. There is a cam to the right of the front plate as shown in the picture. As the clock ticks along, the pin indicated in the gear comes around and slots into one of the silencer cam gaps, turning the cam. The pin completes a full rotation in 2 hours. To adjust the cam to start at the right time set the clock to just before 7. I did 6:45. Then I turned the silencer cam anticlockwise, which spins freely, until it pushed the silencer lever up and was placed just before the drop. Just before the 7AM indicated in the picture. All I then had to do was progress the hands to 7-7:15which made the pin slot into the silencer cam gap and turn the cam so the lever comes down again, unsilencing the clock. That was it. If anyone comes across this issue again I'd be happy to assist. Thanks again to everyone that helped. Hey Transporter! Thanks a lot for the reply. That was a really good explanation and I'm sure it would have made my troubleshooting a lot less painful haha. I'm sure someone will find it useful in the future. Thank you again for taking the time to try and help me out with this.
    • Now I'm completely confused, it would appear that the epilame  is oleophobic  as @Marc states: This oleophobic  behavior can be seen as beading of the droplet (as above) which stops the oil spreading which is supported by what we observe on treated/untreated cap stones (for example), but as @VWatchie states this should make the drops more mobile and is supported by the literature:   A review on control of droplet motion based on wettability modulation principles design strategies recent progress and applications.pdf   However the hole point is that we have less mobile oil so an oleophobic  would see to be the opposite of what we want. In fact this beading and high mobility are desirable properties in things like smart phone covers, see below.  I am fairly sure that epilame doesn't make the droplets more mobile, so maybe its a strange coating with dual properties that are both oleophobic (beading) and cohesive/adhesive resulting in low mobility?? This may explain the high price??  
    • The description there is exactly how it's done, and it's very well written!
×
×
  • Create New...