Seiko 7548a Quartz: not working

[m0g]

Hello there,
I would need some help in troubleshooting the issue for this Seiko 7548 movement.
Prior to disassembly and cleaning, the movement was not working.
I disassemble and cleaned everything. Now I putting back the base movement together with a fresh 386 battery but it is still dead as a door nail.

My diagnosis so far:
* The train wheel is spinning fine
* The battery is brand new and should be good
* The circuit looks fine
* The coil looks fine

I have two different coils: one from a dead 7546, another one for this movement.

Does the movement need the metal retainer in order to work?

Any help or suggestion is welcome.

Thanks for your help.
Cheers

[watchweasol]

Hello   If as you say the train is free and the3 battery is good (have you checked it for 1.5v) it leaves us with the coil and the block.  check the conductivity of the coil and its resistance. If that checks out you need to check the out put from the block and see if there are any pulses reaching the coil.  I have attached the service sheets for the seiko.  On page 13 there is a dignostic flow chart to help you.  

7548A_7549A.pdf 7548A.pdf

[JohnR725]

7 hours ago, m0g said:

The circuit looks fine
* The coil looks fine

the problem with electronic components are they can look good and not be good. You need test equipment to figure out whether the good or bad. Then you need a testing procedure which you can find in the tech sheets that have been attached above.

lacking any test procedure you really kinda stuck as to where the problem would be if you think it's a mechanical problem you could remove almost the entire geartrain just leave the Rotary and as long as you can see it and see if that will turn but it's really best to Houston test equipment

[m0g]

Hello,

I think the best course of action given the resources I have at hand and to get a working donor 7546 and harvest the parts for it.

I'll keep you updated on the progress I make.

Thanks for your help.

[bklake]

If you are still working on this one I think I see a problem.  The screw on the Reset Lever looks incorrect.  It should be a screw that has a square(ish), flat, brushed top.  Look at the parts list.  Other screws from the movement will fit there but are too long and rub the parts under it stopping the movement.  022494 is the part number of this screw. 

Awhile ago, I bought a recently serviced but not working 7548-7000.  I serviced it again, replacing the screws where I found them.  Still didn't work.  I stripped it down again but this time, sorted all the screws per the parts list.  With the correct screws in the correct place, the watch ran correctly.  The Reset Lever screw is just a tiny bit shorter than the others.  It is most easily distinguished by the top shape and finish.  My before pictures of the movement confirmed that a different screw was used on the Reset Lever.  

[m0g]

Hello,

sorry for going silent on this project. I solved my problem in a rather inelegant way. What I did was replacing the circuit and coil with one from a donor 7546. So now, the watch has the wrong movement number, but it does work fine.

Thank y'all for your help!