New ETA 955.412 movement not functioning

[CJ9]

Hi all,

I have a brand new ETA 955.412 movement replacing another with stem damage. With the following steps:

• Place minute/hour wheel.
• Place front plate and secure.
• Place hands (pressed on easily).
• Inserted new battery.
• Ensured crown is pushed fully home.

Trouble is, it doesn't function at all. My first thought is I messed it up somehow! Whilst I'm no watchmaker, my day job is engineer so I'd like to figure it out (if the movement was not bust from purchase).

What I've checked is:

• Changing time with crown works perfectly.
• Date changing functions perfectly.
• New battery (voltage 1.58V) measured at chip.
• Coil measures 1.5k ohm.
• Current draw of around ~2uA.

I'd be grateful for any advice!

Thanks.

[Neileg]

Do you have a quartz watch tester? This will tell you if the electronics is producing a pulse.
Failing a tester an oscilloscope will do that too.
Then is the rotor turning? If you demagnetise a quartz movement, everything works except the rotor is no longer turned by the coil.
The movement may look perfect, even still in ETA packaging, but it may have been demagnetised intentionally or accidentally.
Hope this helps
Cheers Neil


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[rogart63]

Check battery? This movement are pretty simple. You see when the wheels turn? New or NOS ? Could be an old but new movement that has been around for some years. 

[jdm]

All I know is that these 955s -just like most quartz movements- are quite unpredictable.

For one of these watches, I polished case, repaired bracelet ("watchmaker" said bring it to Tissot, LoL) and replaced battery for my sister in law. After few days it came back dead and had to replace move.t.

[Neileg]

Mmm...
In my experience the 955 is one of the more reliable quartz movements. But it's been around for a while and age does a quartz no good.
The mechanics need servicing just like a clockwork watch and damp


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[Neileg]

Mmm...
In my experience the 955 is one of the more reliable quartz movements. But it's been around for a while and age does a quartz no good.
The mechanics need servicing just like a clockwork watch and damp does in the electrics.
A flat battery can be caused by a fault and a new battery may not fix the watch. With a meter you can check the current draw which should be 2 micro amps or less but microammeters are neither common nor cheap.
Most Japanese movements are usually cheap enough that a swap out is the cost effective fix. Swatch's pricing policy on quartz is similar to its mechanical watch policy so a service is a good first step.
I'm not beating the drum for quartz but you need to understand it's different.

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[jdm]

 

In my experience the 955 is one of the more reliable quartz movements. But it's been around for a while and age does a quartz no good.

Well, as it happens, almost every mov.t on heart is described as a"workhorse".. which gives you a good feeling until you meet a broken one

 

With a meter you can check the current draw which should be 2 micro amps or less but microammeters are neither common nor cheap.

Indeed. I saw a digital one which looked good and under 100 Euro, but didn't get it.

 

Most Japanese movements are usually cheap enough that a swap out is the cost effective fix. Swatch's pricing policy on quartz is similar to its mechanical watch policy so a service is a good first step.

I took the 955 apart and put it back up before giving up. Mark has made a great video about it. I found difficult to align pivots in the bridge.

[canthus]

I doubt you could de-magnetise the rotor as I believe it is normally made with what is called a 'permanent magnet'.  I tried to de-magnetise a rotor in my early days of messing with watches thinking it should be de-magnetised.  Despite many efforts I never managed to de-magnetise it (and it still worked afterwards!).  Maybe a very powerful de-magnetiser could do the job but would probably de-magnetise everything within a large range!!!!

[Neileg]

I can only refer to my point about testing for a pulse. A tester at about 30gbp may be too much to rescue one watch but I use mine every time have a quartz movement to fix.
Cheers Neil


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[digginstony]

Back to basics.
1. When you fitted the stem did you keep pressure on the crown whilst tightening the screw. If so it could jam the movement. But the hands will adjust when pulling the crown.
Re fit the stem and see if this works.
You say the hands fitted easily. That's good. But make sure the hour hand has not been pushed down too far. This can cause a jam. It should sit flush on its seating and be perfectly horizontal.
Also I had a Invicta Pro Diver. The quartz version . Awful watch. Fitted with a Seiko PC 21 movement
I demagnetised it on my elma push button. Also on my cheap chinese demagnetiser. I got the hands to spin round but could not get the damm thing to stop working. Still keeps perfect time !.

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[Neileg]

I doubt you could de-magnetise the rotor as I believe it is normally made with what is called a 'permanent magnet'.  I tried to de-magnetise a rotor in my early days of messing with watches thinking it should be de-magnetised.  Despite many efforts I never managed to de-magnetise it (and it still worked afterwards!).  Maybe a very powerful de-magnetiser could do the job but would probably de-magnetise everything within a large range!!!!

You may well be correct. I've never tried to demagnetise a rotor but I'm repeating some frequently read advice. I suppose it would take a lot of zap to neutralise a permanent magnet!
I know that you should never try and clean the rotor with the rest of the parts because it picks every bit of steel dust or swarf.
Cheers Neil


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[rodabod]

Try swapping the old PCB onto the new movement.