A&F axf ETA 2390 Mainspring issue

[cduke]

Hello All,

I have a vintage (1955) ETA 2390 movement that is part of a A&F Super shipmate watch.  The stem turns the winding wheel and stem wheel endlessly.  Is this the deathnail for the mainspring?  I usually hear a clicking sound when the mainspring has broken but I hear nothing.  Is there something else to check why the watch mainspring offers no power?

Thank you

[jdm]

You didn't mention if the watch is running but I'm pretty sure it doesn't.
In any case when trying to understand what goes on with a watch that you have in hand, open the back and observe as much as possible.

[cduke]

12 minutes ago, jdm said:

You didn't mention if the watch is running but I'm pretty sure it doesn't.
In any case when trying to understand what goes on with a watch that you have in hand, open the back and observe as much as possible.

The watch is not running.  The balance wheel is in great shape (well balanced and appears to make an effort to oscillate but with no power from the mainspring...

[HSL]

Since you can see the balance is in a good nick the back is open. The check points you could look at is the wear and tear off the winding stem, the inside of the sliding pinion. Check if the crown wheel is still in place. Is all of the teeth left on the barrell.
If you checked yes on all the above the chanses for a broken mainspring is big.

"Should have said "defektive" since it can have got lose from the barrell arbor too."
 

Edited July 13, 2020 by HSL

[Nucejoe]

 Fault is at barrel arbour , since you hear no sound nor have effective power.

HSL knows that real well,  but funny how he messed up.    lol.

 

[watchweasol]

Hi you might find the attached useful for reference.

3400_ETA 2390,2391.pdf

[cduke]

27 minutes ago, Nucejoe said:

 Fault is at barrel arbour , since you hear no sound nor have effective power.

HSL knows that real well,  but funny how he messed up.    lol.

 

Thanks Nucejoe!  I do hear and see the ratchet and crown wheel turning, just not the clicking sound of a broken spring that I have heard before.

[cduke]

53 minutes ago, HSL said:

Since you can see the balance is in a good nick the back is open. The check points you could look at is the wear and tear off the winding stem, the inside of the sliding pinion. Check if the crown wheel is still in place. Is all of the teeth left on the barrell.
If you checked yes on all the above the chanses for a broken mainspring is big.

"Should have said "defektive" since it can have got lose from the barrell arbor too."
 

Thanks for the instruction.  The ratchet wheel and the crown wheel seem to be fine and turning, just without end.

[Nucejoe]

9 minutes ago, cduke said:

Thanks Nucejoe!  I do hear and see the ratchet and crown wheel turning, just not the clicking sound of a broken spring that I have heard before.

Yes, you hear the click but not the mainspring dislodge, which point to barrel arbour like HSL said, loose at arbour.

[cduke]

Mainspring was broken!  Ordered a new old stock spring.  Can this be installed without a mainspring winder tool?  It seems that it could be transfered directly to the casing from the ring it is delivered in.  I do not own any mainspring tools and do not want to buy a set right now.

Thanks