Girard Perregaux C641 Quartz Movement

[MrRoundel]

Greetings all. I think I may have made a mistake in buying a GP watch that has the 641-875 quartz movement in it. It's a nice looking watch, with a very solid case, but I didn't find out about the caliber number until after I bought it. The seller did not have an image of the movement. Since I usually like GP movements, I thought it was worth a little gamble on getting it running, even if I had to clean it. After the auction ended I found out about these GP quartz movements that are impossible to get parts for, and that the dead ones usually need a circuit that is made of unobtainium.

Since the watch had an old battery (Union Carbide brand) in it I figured that I might get lucky and get it running with a fresh battery. I wasn't counting on that happening since the guy who sold it was a watch guy. It would be hard to believe that he didn't at least try a new battery in there. Anyway, it didn't get it running.

Does anyone know about these rather interesting old quartz movements? I believe it is from the late seventies perhaps? Is there any use in seeing if one of those quartz movement "spinners" could free things up? Unfortunately, it's not like GP provides technical info the way a company like ETA does, so if I take it apart I'll have to take a lot of images as I do. Anyway, any help on this is appreciated. Thanks ahead of time. Stay healthy, all. Cheers.

[AndyHull]

On 3/19/2020 at 10:26 PM, MrRoundel said:

Does anyone know about these rather interesting old quartz movements?

In my limited experience, the most likely problems are, in order of likely hood.

1) Corrosion.

Check the board, check the battery contacts, check for a switch or contact that disengages the battery when the stem is pulled out. Check with a multimeter and good magnification. Check to see if any tracks on the board are damaged by corrosion or screwdriver damage from a previous repair or battery replacement attempt.

2) Dirt.

Clean the mechanism, as you would a mechanical watch.

3) The coil goes open circuit.

Check it with a multimeter. Typically its resistance is of the order of a few k ohms. If its open circuit, or dead short, then you have an issue. Take care with the coil, they are incredibly fragile and very difficult to repair. Replacements are often made from 100% unobtanium.

4) The trimmer resistor (some have trimmer capacitors, so identify which you have) goes open (or short).

5) The crystal goes bad.

If your multimeter has a frequency range, set it to Hz and measure the frequency across the coil. This will be of the order of 1Hz (or 2Hz, 4Hz etc, depending on the mechanism). You could also try measuring the frequency across the crystal, but this is more tricky, as the capacitance of the multimeter leads may kill the oscillator, so this is sometimes a misleading test. The crystal frequency is almost invariably 32768 Hz (32 kHz), as this divides nicely down to 1 Hz.

6) And least likely, the IC is toast.

One other problem, sometimes previous "repairers" have fitter the wrong battery, so check that it is in fact correct, and fitted the correct way round. Some watches, particularly Russian ones are very easy to get the battery orientation wrong.  Also  some cells are 3V, some 1.55V, some are 1.2V and so forth. Fitting the wrong battery or fitting it backwards is the most likely cause of a dead IC, although most modern ones have reverse polarity protection.

Edited March 21, 2020 by AndyHull

[Hondadoug]

Measure carefully and replace it with another swiss movement.

[MrRoundel]

I carefully measured it to be 9 1/8 lignes or 20.32mm. Unfortunately I don't see any ETA movements that are that size. 8 3/4 ligne is as close as I get. If anyone has any ideas of a company who makes a 9 1/8"' quartz movement, I'd appreciate the direction. Thanks.

 

[Graziano]

Hi there , an ETA 959.001  is a 9 ligne , expensive movement .ETA 210.001 is also 9 ligne you can get these new but are around 160-200  USD .Only other suggestion would be go the 8 3/4 ligne and go with a spacer . There is a good book called Quartz watch retrofitting by wesley r. door .This book has loads of information and good to have in situations like yours ,there are many measurements to determine such as thickness for the fitting into the case,dial feet position , hands .But there is most of the time a work around for theses problems .Hope this helps 

[MrRoundel]

Thanks, Graziano.I believe I had seen the 210.001 type movements. I guess they are used in high-end quartz watches, as yes the prices you mentioned are what I saw. I think when GP retrofits one of these watches they use a well undersized movement with a spacer, as you mentioned.

Reportedly even GP will not service these vintage quartz movements. The lack of info on them drops GP down a notch in my personal ratings book, FWIW.

Thanks for the tip on the book. That sounds like a good one to have. If I can't get one right now because of various quarantine attempts, maybe I can find a digital copy. Thanks again.

Everyone out there, stay healthy.

[Graziano]

Hi MrRoundel , if you choose to go down the road of a smaller movement and have trouble finding a spacer there is a product called speedy-fit case filler which is available from cas-ker http://snotboards.com/speedifit.pdf this pdf shows you how to go about it . 

[MrRoundel]

Thanks, AndyHull. That's great information for me to start with. There's no corrosion evident and the contacts at the stem were good. I guess I'll take it apart tomorrow and get it cleaned up. And I get to use the special Moebius quartz oil that I bought over a year ago.

In Henry Fried's book, Repairing Quartz Watches, he mentions a GP design where the stepping motor is comprised of a module. I hope they used that design in this slightly later GP quartz movement. I believe the one he shows was from the C300 series. Thanks again for taking the time to provide such a detailed answer. Stay healthy.

One interesting note is that the battery that was in the watch when I opened the back was a Union Carbide #384. Today it looks like the 384 and 392 are the same, or at least interchangeable. The fact that Union Carbide was purchased by Dow Chemical around the year 2000 tells us how long this battery has probably been in the watch. While the underneath of the battery insulator shows tiny evidence of leakage, it's pretty minor. It looks like what I believe are called dendrite mineralization that is found in opals, and perhaps other geological things. Sort of mini tree branches.

 

Edited March 21, 2020 by MrRoundel
Last paragraph added regarding Union Carbide, etc.

[AndyHull]

6 hours ago, MrRoundel said:

While the underneath of the battery insulator shows tiny evidence of leakage, it's pretty minor. It looks like what I believe are called dendrite mineralization that is found in opals, and perhaps other geological things. Sort of mini tree branches.

The leaking battery can cause thin layers of oxides and other insulating stuff to form on the contacts. It can also etch away the PCB tracks, as can dampness so give everything a clean with isopropanol or contact cleaner, and inspect for damage. Those little dendrites can form in all sorts of odd places due to off gassing of the initial leak, or high levels of humidity. They look pretty under the microscope, but they don't play nice with the PCB or the mechanism.

[MrRoundel]

Thanks, AndyHull. Is household rubbing alcohol sufficient, or do I need to get something else? I do have denatured alcohol and naptha here. I'm wondering if the denatured alcohol might break down the coatings on the PCB or other plastic components.

Looking at the movement carefully under magnification I can see that this caliber wasn't made with serviceability in mind. The PCB isn't very stout. I'd best be careful removing it as I attempt to clean the watch. It will be interesting to see what lies beneath, under the PCB. We'll see if the signs of minimal battery leakage (No salting on the Union Carbide so it may have been before that was put in.) carry through under the PCB. I still have my fingers crossed that I can get the movement going with a clean and oil. Time will be told...or not. Cheers.

[AndyHull]

34 minutes ago, MrRoundel said:

Is household rubbing alcohol sufficient, or do I need to get something else? I do have denatured alcohol and naptha here. I'm wondering if the denatured alcohol might break down the coatings on the PCB or other plastic components.

Rubbing alcohol (which I believe is isopropanol aka IPA), denatured alcohol and naptha should all be safe on PCB material and etch resists and solder masks as  generally these use fibreglass bonded with epoxy, so they are impervious to solvents.

IPA is used as a board cleaner in industry (as indeed were things like trichloroethane and other nasty solvents until relatively recently). 

If you do find something that dissolves epoxy, or printed circuit boards, that isn't nitric acid, I'll be impressed.

Occasionally you may find some older and/or cheaper PCB material that is SRBP -FR2, but generally quartz movements use fibreglass FR4

Whichever type is used, it will not be harmed by most "mild" solvents.

Acetone, alcohol and IPA may dissolve shellac, which is used in mechanical watch movements, so avoid using them on balance forks or where an item is fixed with shellac.

Acetone may dissolve cyanoacrylate, (superglue) which is sometimes used to fix wires on small coils, it will also damage acrylic/plastic watch "glass". The other solvents mentioned should be safe on these parts.

Edited March 21, 2020 by AndyHull

[MrRoundel]

OK, so here's what I was afraid of. There are these little clips that are part of the PCB. It looks like they are soldered to the PCB and use a "C" clip that slides horizontally around the post. If I'm not mistaken I have to somehow lever between the train-bridge and these clips to push them off the posts. I already have the two screws out that hold the PCB so it shouldn't have as much stress on the solders. That said, I'm sure that ideally you would push both clips off at the same time. Sorry about the focus. Both clips are sort of a dumbell shape, with one side open to clip onto the post. The one on the left is at a slightly different angle. Any suggestions? Thanks.

 

[AndyHull]

If you can get a slightly better picture that might help, but zooming in on the first picture, however those clips appear to slide on to the pegs, so you probably need to wiggle the module right, then down slightly to free the top PCB from the lower one. However I would start by checking that the gear moves freely, and perhaps by dropping a couple of drops of lighter fluid on the mechanical parts and trying it again.

Edited March 21, 2020 by AndyHull

[MrRoundel]

Perhaps a bit better image.

 

[AndyHull]

2 hours ago, MrRoundel said:

Perhaps a bit better image.

 

They do look like they clip in from the side, assuming they were not soldered to the top PCB after it was placed..

[MrRoundel]

Yes, hard to say the sequence during manufacture. Maybe that's why GP won't work on these? De-soldering those joints seems like it would be a bit dangerous to the PCB and joint. They may indeed have put the PCB in position under those clips and then hit it with solder. Thanks again, AndyHull.

[JohnR725]

 

http://cgi.julesborel.com/cgi-bin/matcgi2?ref=GP_641

GP-641.PDF

[MrRoundel]

Thanks, JohnR725. Those are great references. I have basically given up on cleaning the movement, as that PCB does indeed look like it as soldered at the posts rather than being clipped on. I'm going to run through the checks based on what you and AndyHull have supplied. I'll report back on any developments. Cheers.

 

Edited March 22, 2020 by MrRoundel

[MrRoundel]

Based on the 641 diagram, I checked the coil resistance at the noted test points. While it may not be open, it does show very high resistance. It is in the order of 3 million ohms. I started low on ranges and showed nothing until I got to the "M" scale. With spec at 9500 ohms and reading at 3 million ohms, I'd say there's a coil problem at the very least. No?

 

 

[jdm]

2 hours ago, MrRoundel said:

Based on the 641 diagram, I checked the coil resistance at the noted test points. While it may not be open, it does show very high resistance. It is in the order of 3 million ohms. I started low on ranges and showed nothing until I got to the "M" scale. With spec at 9500 ohms and reading at 3 million ohms, I'd say there's a coil problem at the very least. No?

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

 

 

[MrRoundel]

Thanks, jdm. All I know is that my meter is one that is made for using with automotive electronics. UEI is brand. As I said, at least I started with the lowest range on ohms setting.

It's possible that I torched the wire within the coil. It's also possible that it was torched before. One thing for sure, watch didn't work at all with new battery. I even hit the pivots with some quartz oil to see if I could decrease physical resistance. No luck.

I guess I'm resigned at this point that it's going to need a retrofit. No telling at this point whether I was just kicking a dead horse, so to speak. But it is certainly a dead watch. Oh well. Thanks for all of the help, folks. Stay healthy out there.

 

[AndyHull]

I suspect the coil was blown before you got to it.

The amount of current pushed out by most modern multimeters into a 9K Ohm load would be tiny, so the risk of blowing it is low, however coil failure is quite common in older quartz watches, particularly ones where a battery has leaked. If you were using an old Avo meter, or one of the really cheap Chinese coil meters, then it might push a more serious current.

More likely the coil failed due to the faulty cell.

Tiny wires dissolve quite easily in the caustic environment that tends to occur after a button cell leaks, or if moisture gets in to the watch.

You may be able to purchase the coil separately for some watches, and you may be able to re-purpose the coil from a similar junk watch, but this is the exception rather than the rule unfortunately.

It would be nice to get that old GP movement working, but the only way I can think of would be to repair the coil, and that is not a job for the faint hearted, and most likely not worth the trouble, unless the watch is particularly valuable, or you simply enjoy the challenge.

I have re-soldered a couple of coils, where the end break was obvious, and on the outside of the coil. This is not an easy task, unless your soldering skills are up to it. If you can solder surface mount components by hand, and have a fine tipped soldering iron and suitable fine gauge solder, and suitable magnification it is doable. Not easy, but doable.

[MrRoundel]

Thanks, AndyHull. Yes, it would be nice to get it running. Overall it's a very nice watch and the quartz movement is of pretty high quality. Maybe not for serviceability, but it is well put together it appears. Virtually every one of these C641 movement watches is either not working or has been retrofitted to a more modern quartz movement. Had I have known how difficult/impossible it is to repair them I'd have passed on the purchase. Still, it's a very nice looker, IMHO, and is worth retrofitting.

The coil on this watch appears to be encased in aluminum/aluminium, rather than having wire that can be soldered. It looks more like an old capacitor than it does a coil. You can see it in the images.

At this point I have carefully reassembled the watch and put it aside until I can figure out what movement to put in it. Thanks again for all of your help and input. Cheers.

The watch has the original marked GP leather band on it. It wasn't worn a lot. I wouldn't be surprised if it has been in the dead zone for quite a few years. I believe it is from the late seventies to early eighties.

[AndyHull]

22 hours ago, MrRoundel said:

The coil on this watch appears to be encased in aluminum/aluminium, rather than having wire that can be soldered. It looks more like an old capacitor than it does a coil

Are you sure that is not the crystal? I suspect the coil is what attaches to those two dumbell contacts we were looking at earlier. As a matter of interest, what is the resistance between the two gold plated dumbell contacts?

Edited March 24, 2020 by AndyHull

[MrRoundel]

No, I'm not sure. Most coils in quartz watches I've seen have visible windings. I just figured it was the coil based on its size, shape, and that it had two leads. That and the fact that the literature that JDM provided the link to has the two pins that the "dumbells" attach to as test points for what they call the coil. That said, they didn't have an obvious connection to what you say may be the crystal. BTW, I'm sure you're right about that. I was basing it mostly on inexperience. Thanks again, AndyHull.

 

 

Edited March 24, 2020 by MrRoundel

[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