Casio divers watch hands not moving, digital works

[Volvodr66]

I need some advice on two Casio AMW-320R divers watches.  They have been living in my watch box for years and I finally decided to get them out and see if I could fix the one.  Allow me to explain.

One works perfectly, the other one the digital part works but the second hand doesn’t move.  In fact, it could be all three hands may not move, I’m not sure because I didn’t check before I started working on them this time and I don’t remember.

My plan was to take parts out of the good watch piece by price and transfer them into the one with the non-working hands to hopefully figure out which component was faulty.  Well, somewhere along the way of swapping parts, I got confused which part went to which watch and now both watches have non-working hands!  Hurray!  Progress! At least I accomplished something.  Now I really have two watches that are identical.

At one point, I had both watches completely apart and I’m sure I’ve got them back together correctly because I can see the axels (I know that’s not the correct term) of the gears through the top plate and can tell they are installed properly.  All three hands move by manipulating the stem and move around quickly when the watch is placed on a demagnetizer.  Just looking for some idea of were I should start.  

My gut feeling is it’s likely to be more electrical than mechanical, as maybe I shorted something out taking the battery out with my tweezers or something?  That’s the only thing I can think of.  If anyone has any suggestions what I can check, I would appreciate it.

Thanks in advance.

[jdm]

5 hours ago, Volvodr66 said:

At one point, I had both watches completely apart and I’m sure I’ve got them back together correctly because I can see the axels (I know that’s not the correct term) of the gears through the top plate and can tell they are installed properly.

Is this the first watch movement that you have taken apart? Isn't that easy to re-assembly them correctly, even for quartz modules.
 

5 hours ago, Volvodr66 said:

All three hands move by manipulating the stem and move around quickly when the watch is placed on a demagnetizer.  

If the pulse doesn't get it restarted, chances are the module id done with, that's not uncommon at all.
Maybe that's a good occasion to move on to a mechanical watch.
 

[watchweasol]

Hi that's a bit unfortuate having two dead ones,  Do these watches have two batteries in some of the analogue/digital have two one 1.55v for the analogue and a 3v coin cell for the digital

[watchweasol]

Hi  Finger trouble.    Can you , post a picture of the watches and their modules please   All may not be lost yet.

[Volvodr66]

JDM, I’ve taken apart a few movements before but only for general cleaning in an ultrasonic cleaner an nothing in the line of diagnosing any type of faults. Also, these were just practice watches as well.  Thanks for the reply.

[Volvodr66]

Watchweasol.  I’ve included a few pictures of the movement of the watch in question.  It’s marked 1374 on the back plate.  
Thanks for your time.

Tom

 

[JohnD]

Quite common for the coil on these to go open circuit. There are two different variations of the movement, one like the one in your pictures with two buttons on the side opposite the crown and another one with one button on either side, no electronic movement parts are interchangeable between the two. It's easy to check the coil for continuity, with a multi meter once yo lift the circuit off...You might be lucky with one watch with a duff coil and the other with a dead circuit.... The resistance of the coil, out of circuit should be around 2k ohms...

Edited June 30, 2020 by JohnD

[Volvodr66]

Thanks JohnD, I’ll pull the coils and measure them and see what I’ve got.

 

[Volvodr66]

JohnD, I think you’re right on with this one.  Both coils are open. Now I just need to see if I can find a place to source them and then see if the other electronics are okay or not.

Thanks.

[JohnD]

9 hours ago, Volvodr66 said:

JohnD, I think you’re right on with this one.  Both coils are open. Now I just need to see if I can find a place to source them and then see if the other electronics are okay or not.

Thanks.

If there  is no obvious signs of corrosion on the circuits they are probably OK. The vast majority of O/C coils are due to ham fisted battery change attempts, where the coil is nicked with a screw driver......