Joined
·
1,578 Posts
I've just serviced a 6139 movement, in good general condition, but the timegrapher showed it running 10mins/day slow. Too slow to be fixed by adjusting the balance. I tried a spare balance assembly from a another movement but got a similar result. The spare balance was from a movement in poor, worn condition, so I wasn't certain my freshly serviced movement had a problem. To be sure, I tried a third balance from a watch I knew to be working well (I checked the watch on the timegrapher before removing the balance). I was happy to find that with the third balance my movement ran OK, spot on.
The first two balances look OK, no visible damage to the hairspring, and the diashocks are clean. Is this issue caused by the springs just weakening with age, or something else?
Cheers, Sam.
The first two balances look OK, no visible damage to the hairspring, and the diashocks are clean. Is this issue caused by the springs just weakening with age, or something else?
Cheers, Sam.