This can be a common problem and there are plenty of reasons why the watch doesn’t want to start ticking again.
Let’s start with the basics and assume you had a go yourself and don’t really know what you’re doing.
You fitted wrong battery. Easily done, for example a 364 or a 377 will both fit into a typical quartz movement battery slot, but the 364 is slimmer so it might not make as good a contact. Unlikely in most cases, but more typical errors include trying a little 346 or a tiny 379 into a watch that needs a beefier battery.
The serial number of the battery is on the old one, but don’t assume the last fitter placed the correct battery in there. Some Casio watches have two batteries, plus they need to have tweezers placed onto the contact points after fitting to reset the movement – usually the contact points are marked but you might need a loupe or magnifying glass to see them.
So, always Google the watch make n model and track down the CORRECT battery serial number. Some have SR numbers, but others are just called 377, 373, 341 etc. Fit a Sony, Renata or decent quality brand – cheap pound shop batteries will not last long.
Dead battery oxidised. You can see this oxide residue sometimes, a fluffy greenish dust will be lurking inside the battery slot. Occasionally, an old battery might split. Once that happens the movement is usually dead, game over.
If you have some petroleum ether then use tweezers to drop a little onto the movement, and carefully clean the battery contact with ether. Use a blower to try and get dust specks out. About one time in ten this might get the movement alive again, depends how long the dead battery has been rotting away for…
You touched the capacitor or battery contact arm and broke it. Again easily done, especialy if you like changing batteries with kitchen knives and £1.99 screwdrivers from the local 8-til late shop.
You see the copper wire coil in the photo below? DO NOT TOUCH IT. It really is that simple.
In general, modern quartz movements fail to start again after a battery change because moisture has got inside. Sometimes, as with the vintage Omega above, it can be 30 years of dirt from an old guy’s wrist, that sneaks in under the snap-on caseback – sweat too. The silicone caseback seal can sometimes rot away and fragments get inside the movement. Nasty.
Another point worth noting on older quartz watches is that they are partly mechanical, they have gears and jewels.
These jewels have a single drop of oil fitted when new, but the oil dries out. If not serviced by a watchmaker, the staff bores a little hole in the jewel, or at least encounters resistance. Game over, watch doesn’t go – dirt and dry jewels can be a fatal combo.
PROCEED CAREFULLY IF YOU SEE A STRAP
OK study the photo below; this is a typical Swiss watch with a retaining contact strap across the battery. See the little slot at one end? That has to be screwed down in EXACTLY the right position, just after you ease the stepped end under the end of the battery slot.
It’s immensely fiddly work, so easy to lose the tiny screw, or damage the retaining strap. As a bodge – not in an Omega – I have cut n shaped a sliver of base metal to do the same job in an old Swiss quartz and incredibly, it worked.
LIMITED LIFESPAN & SHOCKS
One last point; any quartz watch has a limited lifespan, even a prestige Swiss movement. The electrical power from a battery is evened out via the capacitor and it vibrates a quartz crystal at a regular rate – that’s how the second hand ticks. After 20-25 years, most of the crystals stop vibrating, yes, even in an Omega.
So that’s something to think about when investing in a collectable old Swiss or Japanese quartz watch. It could just die and there isn’t a damn thing you can do, because the factory will not be making any spare quartz movements for vintage watches from the 70s-90s.
If you drop a watch it can damage the movement beyond repair too. This can be a typical problem for cheaply made Chinese fashion watches, some of which haven’t even survived being bounced about in a padded bag in the post in my experience.
Hope that helps and if you are keen on watch repair, then invest in good tools, powerful lights, plus a X10 head loupe.