Seiko 7T42 Service Walkthrough

[GeorgeClarkson]

The alarm clutch and winding stem came right after.

[GeorgeClarkson]

Followed by the setting lever for the alarm and the chronograph switch lever A and the 4 coils.

Edited September 8, 2016 by GeorgeClarkson

[GeorgeClarkson]

Now the rotors found their place.

[GeorgeClarkson]

Then the hour and alarm setting wheels and the white minute wheel for alarm.

[GeorgeClarkson]

I then proceeded to install the center minute wheel for alarm and the intermediate wheel for alarm

[GeorgeClarkson]

Next came the minute counting wheel, and its intermediate wheel, followed by the minute wheel in the center (the white wheel).

Edited September 8, 2016 by GeorgeClarkson

[GeorgeClarkson]

And now it was the time to install the second intermediate wheel for seconds counting (what a long name...) and its intermediate wheel

[GeorgeClarkson]

To end the rebuild of the Seiko 7T42 movement, I reinstalled the last 4 metal wheels and replaced the back cover plastic plate. Here's the picture of the movement prior to closing it:

 

[GeorgeClarkson]

While reassembling the movement I took pictures as you saw above, but also a video that was split in 4 parts. The first part is this one. Enjoy.

 

[GeorgeClarkson]

Part 2 of the disassembly video:

 

[Pip]

This is an awesome write up, thank you.


Sent from my iPad using Tapatalk

[GeorgeClarkson]

9 hours ago, Pip said:

This is an awesome write up, thank you.


Sent from my iPad using Tapatalk

Thanks Pip, I appreciate that. I hope to beable to uplouad parts 3 and 4 in the next couple of days.

[GeorgeClarkson]

Part 3

 

 

[clockboy]

George that,s another great walkthrough/Vid. Most would not bother with a quartz (including myself) until watching one of your vids. Keep them coming (if time!!) 

[GeorgeClarkson]

Ladies (if any) and Gentlemen, here the fourth and last part of the rebuild:

Enjoy!

[arkobugg]

On 6.9.2016 at 1:24 AM, GeorgeClarkson said:

And finally the base plate, naked.

Most impressive George!  Its nice to see that all kinds of watch movment are fixable, I have only doing this for some moths. And it gives so mutch inspiration to move on futher....

[RichB]

Hi GeorgeClarkson,

Great rebuild story. I came across this searching for help on my fathers 7T42-6AA. The minute hand stopped working and several UK watch repair shops have told him it cannot be repaired. It has some sentimental value to him and I would like to try and get it repaired.

I was wondering if you could advise if there are common/specific issues with this movement that could cause the minute hand issue and if it is possible to repair? Or would I be able to find other 7Txx movements and swap them into his case?

Thanks in advance,

Rich

[clockboy]

The problem you have is with this movement many of the parts are plastic so if a pinion or wheel breaks the only coarse of action is to replace the movement. If the hand has just come loose on its pinion it could be re-seated. Perhaps a picture might help.

[RichB]

Thanks clockboy,

Here's the only picture I have on me. I will try and get more details of the issue.

Thanks,

Rich

[GeorgeClarkson]

5 hours ago, RichB said:

Hi GeorgeClarkson,

Great rebuild story. I came across this searching for help on my fathers 7T42-6AA. The minute hand stopped working and several UK watch repair shops have told him it cannot be repaired. It has some sentimental value to him and I would like to try and get it repaired.

I was wondering if you could advise if there are common/specific issues with this movement that could cause the minute hand issue and if it is possible to repair? Or would I be able to find other 7Txx movements and swap them into his case?

Thanks in advance,

Rich

Hi Rich, I just received the notification. As clockboy mentioned, these movements are made of mostly plastic parts. A complete swap is, though, not the only solution, also because complete working movements are becoming rarer by the day. That fault you described can be caused by a damaged hour wheel. Replacing the wheel could easily solve the issue, provided you have be the spare to do it. Let me know if I can be of any help, since I do service these watches, and have so some spares left.

[RichB]

4 hours ago, GeorgeClarkson said:

Hi Rich, I just received the notification. As clockboy mentioned, these movements are made of mostly plastic parts. A complete swap is, though, not the only solution, also because complete working movements are becoming rarer by the day. That fault you described can be caused by a damaged hour wheel. Replacing the wheel could easily solve the issue, provided you have be the spare to do it. Let me know if I can be of any help, since I do service these watches, and have so some spares left.

Thanks George, can you point out the hour wheel in one of the photos you’ve posted on this thread? If that is the problem, do you have a spare I could purchase from you? 

It will be about a week before i see my parents and get more info on the issue with the watch.

Thanks,

Rich

[GeorgeClarkson]

The fourth video I posted shows right at the beginning the hour wheel in the center (the grey one) and the date driving wheel (the white one) interacting with one another.

Edited November 22, 2018 by GeorgeClarkson

[GarethRogerson]

Hi my brother has this watch 7T42-6A00 and the circuit needs replacing done anyone have any ideas where we can get one.

[GeorgeClarkson]

2 minutes ago, GarethRogerson said:

Hi my brother has this watch 7T42-6A00 and the circuit needs replacing done anyone have any ideas where we can get one.

Hi Gareth, these movements are not produced anymore, yo your best chance is to search for a spare donor watch on ebay that will not cost an arm and a leg. I do have some spares, but I do not sell them since I use them for the watches I service for my customers, sorry.

[Watchtime]

absolutely stunning George, I wouldn't dare to take it apart..:) Hats off sir.