# Valjoux 7750 - Made a Very Stupid Mistake!!!



## SneezyPorcupine

Hello all,

I have owned a Hamilton Khaki X-Wind Automatic for a couple of years now, and I recently made the stupid mistake of changing the date between the hours of 8pm and 3am...

As such, the date-wheel is now out of whack, although the day wheel still operates as expected. Basically, the date wheel no longer rolls over at the correct time.

But yet a new symptom has now presented itself. When the time rolls past 12am, the day wheel begins to roll over as it should, however, the date wheel does not change until approximately 6am. It used to roll over by 1am.

Also, the date and day can still be quick-set by pulling the crown out to the first position. But, when you pull the crown out to the second position, no matter how many times you go forward in time, the date wheel will not actuate (the day wheel works as intended though). 

So, I don't understand how the date is changing when the watch is operating normal (albeit at the incorrect time of day) but not being engaged when moving the time forward manually.

I would normally assume that the gear/lever that initiate the date change are worn because the date was rolled over at the incorrect time, but that does not answer why it would roll over in one position and not the other...

This brings me to my question. Is there an easy fix to this problem, short of a part replacement? I am fairly adept in basic repairs to automatic movements as I worked at a watch repair center for a few years. But repairs to movements such as the Valjoux 7750 were often performed by veteran technicians.

I am really hesitant to send the watch to Swatch Group Canada, because the last time I sent my Tissot automatic (another 7750) in for service, they took a full 11 weeks to have it back to me. I have spoken to my go-to watchmaker, and he was adamant that the date-wheel mechanism needs replacement and he is currently working on getting me a price on parts. But he really did not take a look at the watch for very long and did not open it as he was fairly busy.

Any advice or knowledge in the matter is greatly appreciated, folks!

Thanks,

Sneezy


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## Nick1016

Well, you certainly know a lot more about watch repair than I do based on your past experience, but I can tell you two things I've been told:

(1) the 7750 is a beast to work on; and
(2) the 7750's quickset day-date mechanism is very tempermental--I've always been told to be extremely gentle when setting the day and date on a 7750.

So unless you don't trust your local guy, my guess is he's probably right about what needs to be done. I'd be inclined to have him do the work--he's probably cheaper than Swatch Group, and certainly faster.

One thought I had is that if the date continues to rollover at 6 a.m., I might just deal with it and wait to have the issue fixed when it's time to do a full service on the movement.


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## SneezyPorcupine

Hi Nick, 

Thank you for the prompt reply. I agree that the 7750 is one of the hardest movements to work on, primarily due to the fact that unlike its ETA counterparts, it is built to be a chronograph from the ground up, as opposed to having a chronograph module added to the base mechanism. As such, you cannot simply remove the piggy-back chronograph module and work on the actual movement. 

Concerning my Hamilton, the watch is still under warranty. However, I do not want to send it to Swatch Group, firstly because of the lengthy turn-around, and secondly because if the cost is rather minor, I'd rather have my technician work on it. I have trusted him with more substantial watches than this, and he has always come through. But I wanted to see whether it was something of a minor fix that could be performed easily. 

This does not seem to be the case however. 

Nevertheless, I am still waiting for him to get back to me with a price. And you are correct, it is not too much of a nuisance that the date rolls over later, but the problem is the fact that when trying to get the AM/PM correctly, it creates a lot of headache. Especially when setting the 7750, it has been designed so the date-wheel rolls forward, while the day-wheel rolls in reverse. 

Also, the Hamilton is not the only watch I wear and I do have to reset it a couple of times a week, when it depletes its power-reserve. So setting it again during those periods has become quite cumbersome. In any case, there is also the fear of whether it will cause more damage in the long run. So, I am keen on getting it repaired as soon as possible.

Unfortunately, there isn't a whole lot of information available on the repair of the 7750, which is why I turned to WUS.

Thanks again!


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## Nick1016

SneezyPorcupine said:


> Nevertheless, I am still waiting for him to get back to me with a price. And you are correct, it is not too much of a nuisance that the date rolls over later, but the problem is the fact that when trying to get the AM/PM correctly, it creates a lot of headache. Especially when setting the 7750, it has been designed so the date-wheel rolls forward, while the day-wheel rolls in reverse.
> 
> Also, the Hamilton is not the only watch I wear and I do have to reset it a couple of times a week, when it depletes its power-reserve. So setting it again during those periods has become quite cumbersome. In any case, there is also the fear of whether it will cause more damage in the long run. So, I am keen on getting it repaired as soon as possible.


Got you...I do agree, this would be a real pain if you frequently reset your watch. So yes, under these circumstances I think I agree that it's best to get it fixed right now than risk doing more damage.



SneezyPorcupine said:


> Unfortunately, there isn't a whole lot of information available on the repair of the 7750, which is why I turned to WUS.


Maybe try posting a similar post in the watchmaking forum? Sorry I couldn't be more help other than to give you some anecdotal info (that you already knew, I'm sure)...I just felt your pain and figured I'd respond! Good luck.


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## slashd0t

I've done this with my 7750 probably 5-6 times by accident and thankfully no issues at all! The date did click a few times, then I realized what I was doing and stopped. :think:

Now from now on I'm going to make an effort to ensure my clock is set to the right time before adjusting the date :thanks


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## Progger

A very common issue with the ETA/Valjoux 7750 indeed. It is NOT a difficult fix, but it involves a few parts being replaced and you'd have to decase the movement and have the hands and dial removed. Gaining access to the day-date module from behind the watch is A LOT of unnecessary work.

I *believe* the culprit to be the double corrector, but other possibilites include the date indicator and day star driving wheels. Some of these parts might have been bent during your attempt to set day and date while in the forbidden time range.

Given your background, you should definitely take a look at: http://www.eta.ch/swisslab/7750/7750.html . Once there, click at "disassembling". Believe me, it's worth it if don't know it yet.


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## filmjuicer

I had a similar problem with my Jazzmaster Auto Chrono--the date was changing at the wrong time (although the quickset still worked fine, I think). So, I sent it to Nesbitts in Seattle (under warranty) and they fixed it. I think it may have just been a hand alignment issue, but I'm not sure. They took care of it and checked everything else out, just to make sure. It took less than two weeks, if I remember correctly.

My point is, if it's under warranty, just take it or send it to your nearest authorized repair center--it doesn't have to be the Hamilton/Swatch factory one as long as it is listed in your manual or online as an authorized agent, you should be fine. (Not sure of the Canadian options, but there are quite a few in the US.)


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## Agitater

If you're in or near Toronto, get a second opinion on the watch from Vik at Canadian Watch Imports on Spadina. He's about the best in the city. Tell him that Dr. Carson sent you.


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## ribrd7282

You do need to be careful. I made that mistake on one of my khaki auto chronos o| and will eventually have to have it serviced. Mine still flips the date and the day, but they now operate 12 hours apart from each other. The date flips at midnight and the day flips at noon. Between this fix and a standard overhaul and lubrication I'm looking at about $ 400.o|
I won't forget again.


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## bmwfreak

You guys should check out this thread in the Tag forum. Nice video of the source of the problem with changing date on 7750.

https://www.watchuseek.com/showthread.php?t=409027


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## ctaylor4874

I have a Hamilton with a valjoux 7750 movement. The day doesn't change until nearly 3 am. Is this normal or is it broken?


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## Gianna's Dad

ctaylor4874 said:


> I have a Hamilton with a valjoux 7750 movement. The day doesn't change until nearly 3 am. Is this normal or is it broken?


It's just not working correctly. If you can live with it until it needs servicing, then I'd do that.

Some people are picky and want it to change over at the crack of midnight, that ain't me. I think mine changes arounf 12:15-12:25, it always has. No worries.


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## dingmah

Gianna's Dad said:


> It's just not working correctly. If you can live with it until it needs servicing, then I'd do that.
> 
> Some people are picky and want it to change over at the crack of midnight, that ain't me. I think mine changes arounf 12:15-12:25, it always has. No worries.


My date flips at 12:45am, and day flips over at 12:50.


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## DetCochese

I know this is an old thread, but it saved me some potential for heartache with my 7750 movement.

Thanks!


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## WichitaViajero

I second your comments!


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## The_kman

I believe Breitling installs date moduls on their 7750's to prevent this, am i correct?


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