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ETA Calibre 955.112 Service Walkthrough

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There’s no shortage of service walkthroughs for this and similar ETA quartz calibres on the Internet, and here on WRT. Nevertheless, I thought it would be good fun and educational to create my own walkthrough, and here it is now!

Only having experience of servicing mechanical and automatic movements, I truly learnt that a quartz movement is not “just a time telling battery device”, but indeed a mechanical movement, except that the power source isn’t a mainspring but a battery and that the escapement is made up of electronics (no escape wheel, pallet, and balance). So, just like a mechanical movement, a quartz movement has a train of wheels, a setting mechanism, a dial train (motion works), and in this case calendar works.

The watch belongs to my father who got it as a gift from my mother at his 40th birthday in 1979 (41 years ago!). He asked me if I could fix the crown which had come loose from the stem. So, I glued the crown back to the stem using Loctite 638. Perhaps not the ideal glue but at least the crown will never come loose again. Anyway, I thought to myself; why not try and give it a complete overhaul!? After all, it had never been serviced and I wanted to learn more about quartz watches and return a perfectly working and clean watch to my much-appreciated dad.

One of the things that surprised me while taking this movement apart was that the parts are very small. Smaller than the parts in an averagely sized mechanical movement and that was a bit of an extra challenge. So, before servicing a quartz movement I think it’s a good idea to gain some experience servicing a few averagely sized mechanical movements first.

Both the disassembly pictures and the assembly pictures basically mimic and complements @Mark's videos How to service a quartz movement. ETA 955 412. Watch repair tutorials” and How to service a quartz movement. Part 2. Assembly. ETA 955.412” which I used for guidance (Thank you!). However, my walkthrough includes lubrication suggestions according to ETA’s technical communication which are intentionally omitted in the videos to save time. For reference I also used the video Quartz Service ETA 955.112, @HSL's quartz movement walkthrough, and @Lawson's walkthrough (Thank you!). All part names I’ve taken from ETA’s technical communication.

So, without further ado.

ETA Calibre 955.112 Disassembly


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