Seiko Quartz 7123-7050 Battery Replacement

[paulb]

Hi

 

I'm hoping that someone here might be able to help with the problem I have encountered when trying to replace the battery on my old Seiko.  I bought the watch new in 1979 and wore it as my daily beater for many years, before it got downgraded to 'garage / workshop' use, and somehow it got lost within our crowded house and I'd actually written it off as gone forever.  However it unexpectedly turned up again recently so I thought I'd have a go at bringing it back to life with new battery, glass and gaskets.

 

Having changed many batteries on a variety of watches, that didn't worry me so I concentrated more on the glass replacement, which is the first I have attempted.  Not sure if it was beginners luck but the replacement parts (sourced from Cousins) worked just fine and the glass went in very well - thanks to having the right tools.

 

Imagine my surprise and frustration when the new battery just refused to stay in place - I can't see any way to counteract the spring in the underside contact.  I'm pretty sure that there wasn't any restraining mechanism that may have been lost, but I could be wrong of course.  Lesson learned here though - take reference photos before staring work!

 

Any hints or advice as to where I might be going wrong would be most welcome.

 

Thanks

 

Paul

 

Here are four views of the battery compartment:-

 

[Chainstay]

Hi PaulB

 

I did a google image search on "Seiko 7123A", and in most photos it seems that the battery is kept in place by the brass spring closest to the coil, but in your watch that spring looks a little bent. But again - I'm a newcomer so I recommend you to wait for more experienced answers. Good luck anyway.

 

Pauli

[paulb]

Thanks Pauli, that's a good point.  I'll have a closer look at the spring & see what can be done with it. 

 

Cheers

 

Paul

[digginstony]

I think chainstay is absolutely correct. By the coil is the retaining spring. It looks a little short as though a bits broken off or it needs to be re shaped with a little fiddling about with. When changing the battery with this type of retainer I always like to loosen the screw and swing the arm out of the way. Fit the battery and swing the arm back and tighten the screw.

Sent from my SM-G900F using Tapatalk

[digginstony]

Or re looking at your photos, loosen the screw and lift, just to take the tension off the spring. Be careful not to touch the coil

Sent from my SM-G900F using Tapatalk

[paulb]

I think chainstay is absolutely correct. By the coil is the retaining spring. It looks a little short as though a bits broken off or it needs to be re shaped with a little fiddling about with. When changing the battery with this type of retainer I always like to loosen the screw and swing the arm out of the way. Fit the battery and swing the arm back and tighten the screw.

Sent from my SM-G900F using Tapatalk

 

Or re looking at your photos, loosen the screw and lift, just to take the tension off the spring. Be careful not to touch the coil

Sent from my SM-G900F using Tapatalk

 

Many thanks, I'll give that a go.

[JohnR725]

I've attached the service manual where you can see sort of what the positive terminal looks like. Visually to me it looks just about right but it's been a very long time since I've seen one of these. The other thing that comes up is the battery has to be the right shape there is no insulator and the wrong shape battery doesn't fit correctly. Then when the batteries in what happens if you put the back lot does the back hold the battery in place? Because the positive terminal does not go across the top of the battery like you see on other watches some of these the battery will literally fall out of the back is off.

Seiko 7123A.pdf

[paulb]

Many thanks for this John.  I do have a direct replacement for the battery so unless there are any minute size differences between the new and old 389, then I wouldn't expect any problems.  Kicking myself for not taking reference photos as I took the back off etc, but from memory the battery was firmly held in place without the back being on.  I'll experiment at the weekend with loosening the terminal screw to see if that makes it easier to seat the battery and then tighten up to see if this provides the 'lock'.

 

Cheers

 

Paul

[digginstony]

I'm a bit in the dark here but does the watch work when the battery is held in place with your finger. If not definitely the terminal part has snapped off. Loosen screw and try repositioning the terminal slightly. If that doesn't work.undo the screw and take the terminal off. A staking set would be useful but if not. Use a small hammer and VERY gently hammer the end part to increase its length to make a contact; If that doesn't work you can try and find a replacement part. Fit another movement if the watch has sentimental value

Sent from my SM-G900F using Tapatalk

[paulb]

Apologies for the long absence but life has a habit of keeping me away from my watch projects, and today is the first opportunity to give things another go.

I was just beginning to think that the battery was never going to go back in when all of a sudden it did!  Turns out the positive terminal locates against the side of the battery, although it is very fiddly to achieve this, but once in place it does seem very secure.

I've added a photo to show what it should look like and as you can see the positive terminal is not quite fully seated, although it is screwed tight.  Having got the battery to stay in situ I wasn't minded to start fiddling again!

I've also added a photo of the finished article.  The face was in perfect condition, so I just replaced the glass and cleaned up all the metalwork.  No attempt to get any of the dings out of the case - partly because I don't have the equipment or time, but mainly because they are part of our history together.

Once again many thanks for all of your help.

Regards

Paul 

[sftigger13148]

JohnR725

You attached Seiko 7123A.pdf to the post, but the file downloads as an empty file for me.

Could you repost the file?

[paulb]

9 hours ago, sftigger13148 said:

JohnR725

You attached Seiko 7123A.pdf to the post, but the file downloads as an empty file for me.

Could you repost the file?

Try these, they should be ok.

Regards

Paul

Seiko 7123A.pdf

Seiko 7123 Tech Manual.pdf

[sftigger13148]

I have a similar issue.  I have a Seiko Quartz 7123A that I have worn as my only watch since 1980.  A week ago I replaced the battery due to the "second hand moves every two seconds" indication of a failing battery.  When I put it together the second hand made a few attempts to move but only moved back and forth a few times before stopping altogether.  I see in Paulb's photo that the Positive terminal is bent up so as to only touch the side of the battery.  Mine appears to be flat and goes across the top of the battery (as far as I can tell.  When I took the case back off the battery popped right out).

Would it make any difference if the terminal went across the top of the battery?  My terminal seems pretty long and would need to be bent to fit the way the one in the picture seems to.  Forgive me but I'm confused about which is correct.  I also don't see why it should matter as long as it is contacting the positive side of the battery.

Thank you also for posting the manual.  Although it doesn't really clear up the terminal issue it did enable me to check that I hadn't damaged the coil block.

[JohnR725]

The positive battery contact is strange in these Seiko's. As you've noticed a lot of times the back is required to keep the battery in place. Then I've attached some images the service manual that's not outstanding but does give you a clue of what it should look like. Another image off the Internet where you can better see were the contact is supposed to be. Then Paul's positive contact isn't quite where it's supposed to be. Notice the red line I drew that is supposed to be parallel to the end of the coil. The circle is supposed to be over the indent and you can see it's off a little bit.

So the contact is at the angle to provide side pressure on the battery. Then it requires the back to hold the whole thing together. You're not supposed to get creative and bend the strap to go across the top although that would work providing you can still get the back on and it doesn't make it too thick.

Then when was the last time this watch was serviced?

[sftigger13148]

So I took the back off and tried to form the contact to more closely match the diagram and pictures.  It felt odd when I touched it and then it snapped right off.

Hasn't been properly serviced in quite a few years.  When I broke the crystal and took it to a highly recommended jeweler they put a generic crystal in it.  They said they cleaned and adjusted it but I never quite believed them.

I went to a local jeweler who has changed the battery in the past and replaced the band a few years ago (the pins had worn out).  He did not have a replacement contact and suggested that sending it to Seiko Service Center probably wouldn't do me any good due to the age of the watch.  He did suggest that I go see "a guy" who set up a watch repair shop in the back of an antique store.  That guy had a tin with 7123 written on it, and a complete mechanism.  He took the contact from that movement and installed on my watch.  No good.  He did find the broken piece of the contact, and then proceeded to pull out other tiny bits of metal (filings from the case).  After almost total disassembly and reassembly he got the watch running.  Other than wanting to bet that it wouldn't keep running for more than two weeks I was very pleasantly surprised.  From his shop, bench and collection of parts it's apparent that he has been doing this for quite some time and knows what he's doing.  He also verified that the crystal is a cheap generic.  He checked his parts stock but the Seiko package for my crystal was empty.  If it keeps running for more than three weeks I'll start searching for a crystal (310T57AAS0).

I thank you all for your interest and assistance!  I have neither the tools or the steady hands to do the work this guy did.  Those tiny bits of metal were what was stopping the motor from doing it's thing.....

I only wish he hadn't kept telling me that it's going to stop someday and be dead - for good.

Thanks again for all your help!

[rogart63]

18 minutes ago, sftigger13148 said:

So I took the back off and tried to form the contact to more closely match the diagram and pictures.  It felt odd when I touched it and then it snapped right off.

Hasn't been properly serviced in quite a few years.  When I broke the crystal and took it to a highly recommended jeweler they put a generic crystal in it.  They said they cleaned and adjusted it but I never quite believed them.

I went to a local jeweler who has changed the battery in the past and replaced the band a few years ago (the pins had worn out).  He did not have a replacement contact and suggested that sending it to Seiko Service Center probably wouldn't do me any good due to the age of the watch.  He did suggest that I go see "a guy" who set up a watch repair shop in the back of an antique store.  That guy had a tin with 7123 written on it, and a complete mechanism.  He took the contact from that movement and installed on my watch.  No good.  He did find the broken piece of the contact, and then proceeded to pull out other tiny bits of metal (filings from the case).  After almost total disassembly and reassembly he got the watch running.  Other than wanting to bet that it wouldn't keep running for more than two weeks I was very pleasantly surprised.  From his shop, bench and collection of parts it's apparent that he has been doing this for quite some time and knows what he's doing.  He also verified that the crystal is a cheap generic.  He checked his parts stock but the Seiko package for my crystal was empty.  If it keeps running for more than three weeks I'll start searching for a crystal (310T57AAS0).

I thank you all for your interest and assistance!  I have neither the tools or the steady hands to do the work this guy did.  Those tiny bits of metal were what was stopping the motor from doing it's thing.....

I only wish he hadn't kept telling me that it's going to stop someday and be dead - for good.

Thanks again for all your help!

That is very common problem with quartz watches. He obviously did now what he was doing. Lets hope it runs for more the a couple of weeks. I did service a nice Seiko 7123 for my father. Runs like a dream. One big problem with this movements is the cannon pinion.