I have to admit, I am pretty proud of myself on this one! Last night, my brand new Top Gun 3799 stopped working after I played with the chrono. Yeah I know... The movement completely stopped and could not be restarted.
I decide to immediately open her up and look at what was wrong. I found a loose part under the anti-magnetic cover.
According to the ETA 7750 Swisslab ( http://www.eta.ch/swisslab/7750/7750) This loose part is called the clutch spring.
The clutch Spring should be installed lie this:
After investigating as of why did this spring decided to come off I noticed that my movement did not have the following screw in place anymore:
From that moment I knew the the missing screw must have fell off and jammed the mechanism. I then decided to take the following part off to get beter access to potential zone where the screw might be hiding.
BIG MISTAKE!!! Not only , there is no place to hide for this screw under that bridge, but that bridge is a real PITA to put back in place! But with patience, I managed to get it back where it needs to be.
I then removed the balance wheel assembly since the screw use to be sitting right over that area.
Guess what! The bugger was hiding right here!
After a closer look at this screw, I realized that it is a pin that should be pressed in place. Not screwed! Trying to screw this pin in place I noticed that the head was off center. At this moment I have attributed this to poor manufacturing standards. So I decided to use pliers to give the pin a bit of texture so it would hold in place once I press it back in its hole. I also applied a small amount of red loctite to it.
All the movement was reassembled and the balance wheel was oscillating again! Woohoo! But the chrono was not working. Many minutes playing with the clutch lever made me realize that the screw (Pin) that fell off had an off center head for a specific reason. The head acts as a rest for the clucth lever and by rotating that pin it moves the rest position. This cam action has an effect on the load applied to the gear providing power to the second hands of the chrono. Too much load and it kills the movement. I had to find the apogee of the cam by starting the chrono and adjusting the cam until the seconds gear would be running smooth.
My Top Gun is now all back together and all functions are working like nothing ever happened! I am so happy!
First Time ever performing a job of this complexity on one of my watch.
I decide to immediately open her up and look at what was wrong. I found a loose part under the anti-magnetic cover.
According to the ETA 7750 Swisslab ( http://www.eta.ch/swisslab/7750/7750) This loose part is called the clutch spring.
The clutch Spring should be installed lie this:
After investigating as of why did this spring decided to come off I noticed that my movement did not have the following screw in place anymore:
From that moment I knew the the missing screw must have fell off and jammed the mechanism. I then decided to take the following part off to get beter access to potential zone where the screw might be hiding.
BIG MISTAKE!!! Not only , there is no place to hide for this screw under that bridge, but that bridge is a real PITA to put back in place! But with patience, I managed to get it back where it needs to be.
I then removed the balance wheel assembly since the screw use to be sitting right over that area.
Guess what! The bugger was hiding right here!
After a closer look at this screw, I realized that it is a pin that should be pressed in place. Not screwed! Trying to screw this pin in place I noticed that the head was off center. At this moment I have attributed this to poor manufacturing standards. So I decided to use pliers to give the pin a bit of texture so it would hold in place once I press it back in its hole. I also applied a small amount of red loctite to it.
All the movement was reassembled and the balance wheel was oscillating again! Woohoo! But the chrono was not working. Many minutes playing with the clutch lever made me realize that the screw (Pin) that fell off had an off center head for a specific reason. The head acts as a rest for the clucth lever and by rotating that pin it moves the rest position. This cam action has an effect on the load applied to the gear providing power to the second hands of the chrono. Too much load and it kills the movement. I had to find the apogee of the cam by starting the chrono and adjusting the cam until the seconds gear would be running smooth.
My Top Gun is now all back together and all functions are working like nothing ever happened! I am so happy!
First Time ever performing a job of this complexity on one of my watch.
