Girard Perregaux C641 Quartz Movement

[JohnR725]

I found another picture of your movement online just to compare.

To understand things better I found some patents for you. The second link is for watch design similar to yours but not exact. But the concept ideas are they are you should build identify the components from this patent. The third link is for the stepping motor.

So you end up with a semi flexible circuit board. Flexible in some places stiff in others. I'm reasonably sure the green covering is a protective insulation whether or not there is any clear insulation anywhere else I can't tell from the photographs. If I was measuring the coil resistance I would try to measure the gold connecting posts or pins that are sticking up as they shouldn't have any insulation on them.

Then the first link unfortunately is not your watch but it does show what happens when you take the circuit board of. Unfortunately the clips found on this watch look much easier to remove than yours. So I'm guessing from the pictures in the patent that once the circuit board comes off  should be a couple of screws and you can remove the entire stepping motor. Unfortunately with these early designs of embedded coils probably isn't much you can do if you're coil is open.

The only other thing I saw that I had a minor concern of and I can't see from your photograph is the negative battery contact. You can see a nice contact surface but the part where it goes up to the circuit board should be insulated their otherwise it's going to touch the outer shell the battery in short the battery out.  The way you can check for this is on the drawing of tests it shows measuring the battery voltage with the battery in the watch on the circuit board itself.

http://www.crazywatches.pl/jaeger-le-coultre-gp352-master-quartz-1972

https://patents.google.com/patent/US3778999?oq=US3778999

https://patents.google.com/patent/US3747320A/en?oq=US3747320

 

[MrRoundel]

Thanks for your troubles, JohnR725. All good reads/references.

I did find an image of a 350 series GP quartz on Hodinkee. It showed the types of clips you mentioned. They do indeed look easier to deal with.

I will pop the back off today and take a look at that area where the negative contact drops down under the battery. Thanks again. Cheers.

C350 image ~ half way down.

Edited March 24, 2020 by MrRoundel
Proper attribution

[FLwatchguy73]

This may have been addressed already, but I'll rehash just the same. Have you tried turning the trimmer? I have done that with no less than 4 vintage quartz moments that were sold as dead, but sure enough, off they went after. Simple and non invasive. Worth a shot if you haven't already tried.

[AndyHull]

Jiggling the trimer can't make it any worse than it currently is. I suspect the trimmer is a small value capacitor,  (of the order of a few pF), but it may be a variable resistor. Either way a little bit of a clean with contact cleaner or alcohol, and a little bit of a fiddle with a screwdriver is worth a try.

[JohnR725]

15 minutes ago, AndyHull said:

Jiggling the trimer can't make it any worse than it currently is. I suspect the trimmer is a small value capacitor,  (of the order of a few pF), but it may be a variable resistor.

From the picture it's a classic ceramic variable capacitor.

This is where having test equipment for electric watches would come in handy. Like a timing machine that can pick up the frequency of the quartz crystal oscillating. Then when you're playing with your trimmer you could see if that has any effect. You do want to be careful with the trimmer they can be broken if you press too hard.

Then just to make sure were all on the same page of which is the trimmer capacitor I've extracted the image from your picture. You'll notice on the image the silver colored part is one half of the plate of the capacitor. Underneath is the other half bringing them together parallel gives you your maximum capacitance. 

[AndyHull]

4 hours ago, JohnR725 said:

5 hours ago, AndyHull said:

 

From the picture it's a classic ceramic variable capacitor.

Agreed. The construction suggests it is almost certainly a variable capacitor.

One slightly off topic point. A lot of recent low cost multimeters are able to measure frequency (Hz), and I've had good success with these.

My main multimeter (the fact that I have several multimeter will probably not come as a great surprise), can measure the .5, 1, 2 or 4Hz on the stepper, and the 32786 Hz of the crystal on most of the quartz watches I've tried it on.

If you don't have access to a real quartz watch timing machine a multimeter with a frequency range may well be the next best thing.

[jdm]

11 hours ago, AndyHull said:

A lot of recent low cost multimeters are able to measure frequency (Hz), and I've had good success with these. My main multimeter (the fact that I have several multimeter will probably not come as a great surprise), can measure the .5, 1, 2 or 4Hz on the stepper, and the 32786 Hz of the crystal on most of the quartz watches I've tried it on.

With my cheap one I can't get a steady measurement at the motor. I haven't tried the crystal yet but I will, have an ETA 255 that runs just a bit slow, but enough for the owner to ask for a replacement. 

[watchweasol]

Like Andy I have several meters digital and an analogue for watch work. If you are into quartz watches Israel Angeles in the Phillipines (master watch and Clockmaker) has designed and build several quartz watch testers ( I have two )and they are tailored for the job   They are not cheap but they are good I will post a couple of pictures of them later,  both simple to use and understand. One has an audible pulse with leds and the other just led.

[AndyHull]

38 minutes ago, jdm said:

With my cheap one I can't get a steady measurement at the motor. I haven't tried the crystal yet but I will, have an ETA 255 that runs just a bit slow, but enough for the owner to ask for a replacement. 

 

With my Uni-T 61B  I have had some success measuring both the crystal freq and the motor, but the low frequency of the motor is actually outwith the stated spec of the meter (but it does seem to work).

Obviously I cannot state whether any particular meter will work for certain, but this one seems to, in the limited number of cases I have used it. This meter (and many others) are based on the DTM0660L DMM chip, so others based on that, may work. The el-cheapo $3 ones are based on other chipsets, and generally don't measure frequency.

One other point, if attempting to measure the frequency of the crystal, be aware that the crystal oscillator will probably be affected to some degree by the capacitance of you meter probes, so try measuring across the crystals pins, and also between each pin and ground, as that will give you a better chance of finding a signal. Loading up the oscillator with parasitic capacitance may either affect its stability (leading to fluctuations or no measurement), or may simply stop it oscillating completely.

You should also be safe to probe the other pins on the chip with a modern meter in frequency mode, so you may find signs of life on the other pins, even if you are struggling to measure the oscillator directly. Finally, if you have an oscilloscope then that will give you a much better chance of seeing what is going on, and oscilloscope probes are far less likely to interfere with things than simple multimeter leads.

[MrRoundel]

Adjusting the trimmer capacitor didn't have any effect on the movement.

This morning I received an alert that a seller on the auction site had NOS parts for the C641movement. After verifying that it was indeed NOS, I ordered it from overseas. Fingers crossed that it works. I'll have to work on removing the old one from those posts. I'll report back once the part arrives to see if I can get some more expert advice on replacing the part. Thanks again, all. Stay well.

 

[MrRoundel]

Just an update on the status of the replacement PCB that's on the way by slow canoe from Portugal. It arrived at the International Service center in the US last week, so maybe I'll get it this week. I really need to find something to do right now. I'm going out of my mind. I'd better get into a watch today. I'll report back when the part gets here and is installed.

I want to thank you guys for all of your expert assistance. I looked over this thread and it blew my mind how much great information you provided. A few of them should qualify as sticky must-reads for anyone working on a quartz movement. Thanks again. Cheers.

 

[MrRoundel]

Update: I received the circuit for my GP 641 quartz movement the other day. It took about 6 weeks to get here from Portugal.

I started to tear the watch back down for a cleaning. I really wanted to attach the circuit to see if it started running before cleaning it but it seems risky to remove the PCB again, etc. I won't be able to find another for a long while if I mess it up. As I worked to get the PCB detached, I discovered that the clips around the posts probably to straight down the posts rather than from the side. Something about the dog-bone design made me think that they'd clip from the side.

So now I'm think that I'll clean the movement first, but I'm hesitant because my cleaning solutions are getting a bit long in the tooth. They seem to always leave residue behind. Eventually it dries but it leaves ghosts of the solution on the surface. I just don't think a quartz watch will tolerate any film being left behind.

So is there a recommended cleaner, or type of cleaner to use in my ultrasonic for cleaning quartz movements? I've been using the petroleum based L&R solutions but they  just don't seem to age well, whether they're used or not.

Any opinions are appreciated. I'm going to wait until I get fresh solutions before I tear the movement down anymore. Thanks ahead of time. Cheers all.

 

MrR

[MrRoundel]

Well, I cleaned the movement and oiled the few pivots with Moebius quartz oil. I even tore down the encased stepping motor to do the best job I could. That was a bit of a bear to get back together without any technical manual. AWCI had one but I'm not a member so I couldn't access it.

Sadly, after all of my efforts, the watch still doesn't run. I'd have to say that the circuit that I got from the guy in Portugal, and waited over one month to receive, was defective. The movement is clean, the battery is good, there's only the electronics, right?

Oh well. Live and learn. I guess someday I'll be retrofitting it. It's sad because it's such an interesting early quartz movement. It appears to be of high quality, but apparently the design wasn't destined for a long life. 

At least it's put together and out of my pile for a while. Thanks for all of the help, gents. Maybe I'll get to it again in the not so distant future and perform the suggested checks. Cheers all.

 

Edited June 11, 2020 by MrRoundel

[JohnR725]

3 hours ago, MrRoundel said:

Sadly, after all of my efforts, the watch still doesn't run. I'd have to say that the circuit that I got from the guy in Portugal, and waited over one month to receive, was defective. The movement is clean, the battery is good, there's only the electronics, right?

This is where it would be nice to have test equipment for quartz watches. Because you can't look at the watch and decide that because it's not running that the problem is unless you can somehow see the flow of electricity and magnetic fields.

 

[sweeney90]

I have literally just stumbled across this post and it reads like a story book. I think I became slightly emotionally invested in the GP working again. Sorry to hear that you couldn’t get it working again and hopefully in the future you can give us an update as I don’t think the story of this watch is finished just yet


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[MrRoundel]

The proprietary stepper motor design seems to have the coil built into the stepper motor case. I was very careful around the coil wires when working with it. Of course that doesn't guarantee that something didn't happen to it, or that it wasn't bad before I got to it. Hmm...yes, a tester would be nice at this point.

Image is from Fried's book on quartz watches. Figures 9 and 10 refer to the earlier 350 series quartz watches, but the stepper motor design is similar.

Would this tester be adequate for my present purposes?

Tester

 

Edited June 11, 2020 by MrRoundel

[MrRoundel]

3 hours ago, sweeney90 said:

...and it reads like a story book.


Sent from my iPhone using Tapatalk

Yes, and I'd sure love to get to the happy ending, if you'll forgive the expression.

[watchweasol]

Hi   the tester, whos link you have posted  I believe is one of the Indian ones from Roshan  I had one of their earlier models and it broke, when taken apart it was pure crap. I salvaged the line release transformer and made another line release with it.. I will photo the two I have got and post them for you.

[MrRoundel]

Thanks, watchweasol!

[watchweasol]

Hi  As promised the two testers.  The one with the led array is the most comprehensive of the two.  The small one has no audio just a led that heart beats the pulses.  The bigger one has audio which can be switched on or off and the state of the health of the watch is indicated by the led array as per the lesgend on the array. both come with full instructions,  Google 

israel angeles watchmaker and you will be able to find the demo videos on both units.

3385 costa about £150  and 3386 £70 or thereabouts.  I find them usefull..  will check coils, crystals pcbs and consumption , just check out the Videos.

His email is   [email protected].         These units are hand build to order by israel angeles him self.       no mass produced stuff.

[MrRoundel]

Excellent. Thanks! I'll see about picking one up from him. Cheers.

 

[watchweasol]

Hi From the net you will find out all about him , He runs and owns a company in Manilla "The Big Tic " I think they call it and a watch repair training school.  The whole thing is afilliated to AWCI so he is no duffer. His story is worth reading. he has a range of his own analysers and associated equipment.           Glad the information was of some use to you              Cheers

[JohnR725]

Not a lot of information available for the India testers but there is this video I found a few of the things are missing from the video? Then a DIY project if you want to pick up the magnetic field which is one of the things you need to test for. Then just some miscellaneous tests stuff the fourth and fifth link more than you probably want to spend but that's quite reasonable considering what it does.

https://youtu.be/V1VpSDa3XyE

https://electronicsproject.org/quartz-watch-tester/

http://www.ofrei.com/page256.html

http://onatelier.co.uk/new-equipment-workshop-quartz-testing

https://webshop.horotec.ch/en/document/article/pdf/USER_MSA19.115_en.pdf

https://www.thewatchsite.com/threads/quartz-watch-tester.44041/

[MrRoundel]

More great info there. Thanks, JohnR275. I wish my electronics knowledge was sufficient to take on the DIY projects, but it's not. While it makes some sense to me, I'd probably be best buying something ready-made. That Horotec is one that I was looking at yesterday, but it a bit cost prohibitive for my hobbyist budget. It would be on the short list though. Thanks for the links, etc. Cheers.

 

[MrRoundel]

On 3/22/2020 at 11:38 AM, jdm said:

Surely it is, a word of caution, you need a low voltage meter (or a voltage dropping resistor) to measure coil resistance, otherwise you may blow it, check recommendations on the attached sheet. Even if your is not an ETA, I don't think the extremely thin wire is much different.

3568_ETA 251.292.pdf 4.49 MB · 7 downloads

 

 

Since I couldn't get my hands on a quartz analyzer anytime soon, I decided to look into testing the coil with my automotive digital multimeter. After I saw that the ETA specs in the attached pdf said to set the tester to 10K ohms to measure what should be around 2K ohms, and I saw that my meter has a 4K ohms setting, I figured I was safe. I tested the coil in an ETA and the voltage from the meter didn't fry it, so I moved on to the GP 641. Based on what I could tell, the two posts that connect from the coils to the circuit (See image from Fried book.) should be the terminal points of the coil wire. My meter shows that the coil is open. Therefore it is quite possible that the circuit is good (As was the original?), and that it is the encased coil that is bad. Does that make sense? That's going to be a tough "get" for a part. Rats.

Will the crystal still pulse when there is a power supply connected, despite having an open coil? Thanks.

Edited June 18, 2020 by MrRoundel
Add question about crystal pulse.