A Bit Of Help With A 7750 Please...

[Atredes]

Hi Guy, first off this website is a great resorce and the youtube channel has taken up quite a few hours of my time looking a teardowns and repairs, so much more insightful than a manual.

 

I recently aquirred a Victorinox with a 7750 movment which has stopped working, immediately I noticed that the rotor was loose, upon inspection all seemed fine with the rotor itself and the bearing is tight with no excess play. The disassembly of a 7750 is far beyond my novice level and it is something that I would like to attempt in a couple of years. My question however is more about the case and movement holder of this model. The tabs that extend from the holder fir into slots on the case itself. The 2 tabs on the movement itself are easily loosened but for the life of me the two screws on the movement holder are the tightests I have ever come accross. It is not possible to get the movement oyt without releasing these two tabs, the dial has an attached tachymeter surround that is bonded to it.

 

If you look at ther picture you will notice a missing screw near the 9 o clock position. I beleive that this screw has dropped in behind the balance wheel and is the cause of this watch not working. I beleve if I can get the movement free of the case and holder it may enable me access to locate this errant screw.

 

Thanks in advance to anyone who chimes in

[Mark]

The case screws are usually very tight as they can come undone easily due to the vibration from the weight.

You could remove the weight and then carefully remove the balance which will give you the ability to inspect the wheels and hopefully locate that screw.

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[Atredes]

Thank you, I will remove the balance and see what I can see.

[Atredes]

ok, I took out the balance wheel, it looks fine and and the spring and ocillation looks good. No sign of the errant screw, I looked around as best I could. I replaced balance, by itself it seems fine but the watch will not start up. All functions eg winding tension, date and time change seem perfect. Aside from complete stripping is there something else that I can look for. The movement looks like its in good shape with no signs of corrpsion or water ingress, most likely it has run without a service and a lot of the movement will be dry, the main thing though initially is to figure out if a screw has lodged somewhere in the movement. When I opened the case I was pretty sure it had not been opened since it stopped, judging by the amount of dirt , skin etc. Any ideas are much appreciated.

[emso]

Well that screw is somewhere there and you need to find it and remove it

br

emso

p.s: sent from my s****y phone so sorry for typing mistakes :-)

[Atredes]

ok, all good. managed to get case screws out and took movement out, took off balance wheel again and put movement into holder, got a big light and loupe and looked around gear train, presto!!! Screw was lodged in on the wheel with the long curved teeth right at the back. Took a little time and managed to get it out without putting any force on the gear train. Replaced balace and watch fired right  up!!!

 

Thanks a lot guys, needed that bit of push to go digging!

[Geo]

Great result, well done sir!

[Mark]

Well done :)

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[WillFly]

:rock: :rock: :rock:

[autowind]

Great result,  you will be better equipped when you get your next non runner.   :thumbsu:

[Lee]

nice one, so satisfying ain't it!