I have no idea if this is an impossible question to answer but I’ll ask anyway.

I’m thinking about buying a jump-hour watch which is advertised as ticking, all dials are moving when set by the crown, but the hour dial isn’t jumping.

is this likely to be a fatal problem or something that should be fixable under service?

thanks for your help.

 

Not impossible to answer - yes it can be fixed. How much to do so is the question...

 

Thanks @Archer. I pulled the trigger. It’s this... nothing special except that my parents bought me one when I was 11 years old for getting into the good school. No idea what happened to that one. I’ve had my eye out for a replacement for a while but they seem to be rather expensive for what they are, and the chrome is rarely in good condition. This one was cheap and looks to be in acceptable condition (although the pictures were rubbish) and I figure if the worst comes to the worst, I could pick up a working donor in a tatty case also cheap and be happy.

It’s a gamble, but not a big one.

 

Luckily, you most likely have the BFG 866 in there. You'll be able to find donor spares without much issue since it was a common jump hour movement. But it would probably be an easy fix. These have a little star gear and a click spring arm similar to the way some date systems work. It might have just found a sweet spot where something got wedge and just needs to be realigned.

Pretty bullet proof on the top side.

If it was a Lord Elgin or Benrus jump hour, we'd be having a different conversation. I have a drawer of spares for those because they aren't fun to find parts for.

P.S. little known secret - If you ever need a crystal, GS CY934 is what you want to find.

Good Luck!

 

Thank you @MoclovFlop, that’s all very good to know. That movement number sounds familiar so I’m guessing I’ve seen it before during my research. If so, it’s reassuring to know this should be a fairly easy repair. And thanks for the heads up on the crystal.