Rolexman Posted August 20, 2008 Report Share Posted August 20, 2008 Well off course it had to happen one day. I messed up the keyless works of my A7750. This is not my first keyless works incident, it happens to me all the time but always on the ETA 28xx series. I found some repair guides on this last type of movement but not on the 7750. Only a link to ETA.ch that doesn't work anymore. So any links or tips on fixing the keyless works on the 7750 would be welcome. Thanks! PS: I don't know why it happend, as I have removed and inserted the stem of a a7750 thousands of times. This time the crown of my Skyland wouldn't 'pop' out any more. So I removed the stem/ crown. Cleaned the spring mechanism in the crown/ stem and oiled it (now the spring in the crown works fine) and gently tried to reinsert it. It locked into the hand wind position but I noticed the rotor spinned with every turn I hand wound (So I knew something was wrong) and I could only hack into the date position not the time setting postition..... I tried reinserting the stem over a dozen times but each time it just doesn't engages like it should Quote Link to comment Share on other sites More sharing options...
RWG Technical Posted August 20, 2008 Report Share Posted August 20, 2008 There are two separate items here. 1. If the rotor is spinning when you wind the watch, the problem is the reversing (click) wheel, it's got nothing to do with the keyless works. Only fix is to either clean or replace the wheel. 2. If you can't pull the stem to the time setting position, the problem is most likely the hacking lever. Once in a while the clutch and hacking lever will get out of position, and the lever will not be engaged into the clutch wheel. There is a fix without a full disassembly, but it involves removing the balance wheel, and pushing the hacking lever back into place from where it meets the balance wheel...not a simple or easy fix. It can be done, but it's challenging. The only other fix, is to get at the keyless works from the dial side and reposition the hacking lever into the clutch gear. RG Quote Link to comment Share on other sites More sharing options...
Rolexman Posted August 20, 2008 Author Report Share Posted August 20, 2008 There are two separate items here. 1. If the rotor is spinning when you wind the watch, the problem is the reversing (click) wheel, it's got nothing to do with the keyless works. Only fix is to either clean or replace the wheel. 2. If you can't pull the stem to the time setting position, the problem is most likely the hacking lever. Once in a while the clutch and hacking lever will get out of position, and the lever will not be engaged into the clutch wheel. There is a fix without a full disassembly, but it involves removing the balance wheel, and pushing the hacking lever back into place from where it meets the balance wheel...not a simple or easy fix. It can be done, but it's challenging. The only other fix, is to get at the keyless works from the dial side and reposition the hacking lever into the clutch gear. RG Thanks Rob, It's definately #2. I also saw your post here and I think I can see the hacking lever holding the balance wheel down. So now my question is, won't I damage the balance wheel/ hair spring if I remove it whilst the hacker lever is holding it down. And what is the best way to remove the balance wheel? What happens if I remove the balance wheel? Will the movement start running? Will I be able to install the balance wheel again without further disassembly etc? Is it as straight forward as removing the balance screw, removing the balance wheel, wiggle the lever back in position, replace the balance and voila? Thanks, your help is much appreciated! PS: Sorry for the edits Quote Link to comment Share on other sites More sharing options...
RWG Technical Posted August 20, 2008 Report Share Posted August 20, 2008 Removing and re-installing the balance wheel, if you have never done it, I don't recommend. Too risky and too easy to damage. Then the only solution is to get access via the dial, and that is not simple either, due to all the chrono springs and parts that have to go back together. I am afraid there is no easy solution to this one, I can't type out a how to for either of these procedures, since it's too complex, and the balance is so fragile I am very hesitant for you to attempt it as you could easily break off the pivots. Sorry I can't offer anymore. RG Quote Link to comment Share on other sites More sharing options...
Rolexman Posted August 20, 2008 Author Report Share Posted August 20, 2008 Removing and re-installing the balance wheel, if you have never done it, I don't recommend. Too risky and too easy to damage. Then the only solution is to get access via the dial, and that is not simple either, due to all the chrono springs and parts that have to go back together. I am afraid there is no easy solution to this one, I can't type out a how to for either of these procedures, since it's too complex, and the balance is so fragile I am very hesitant for you to attempt it as you could easily break off the pivots. Sorry I can't offer anymore. RG Understood... to my local watch maker it is Thanks for your input Rob! Quote Link to comment Share on other sites More sharing options...
RWG Technical Posted August 20, 2008 Report Share Posted August 20, 2008 Understood, if he can remove the balance, tell him that with the stem removed, he can push the hacking lever in place and it will seat correctly into the clutch gear. Keyless works MUST be in the winding position for this procedure to work. I have done it, so it's possible, should be a quick fix. RG Quote Link to comment Share on other sites More sharing options...
Rolexman Posted August 20, 2008 Author Report Share Posted August 20, 2008 Understood, if he can remove the balance, tell him that with the stem removed, he can push the hacking lever in place and it will seat correctly into the clutch gear. Keyless works MUST be in the winding position for this procedure to work. I have done it, so it's possible, should be a quick fix. RG Okay I will tell him, but I don't know for sure if the winding position is correct in my case as I can clearly hear, it is not the 'normal' winding position. Also the rotor never spun before while hand winding so I think it has something to do with the keyless works being messed up. I will tell him what you told me so if he is any good he will get it fixed. Will let you know how it turns out! Thanks again! Quote Link to comment Share on other sites More sharing options...
AstroAvia Posted September 30, 2008 Report Share Posted September 30, 2008 So, how did it turn out? Quote Link to comment Share on other sites More sharing options...
Rolexman Posted September 30, 2008 Author Report Share Posted September 30, 2008 My watchmaker fixed it during the service but he had to remove the hacking lever (or a part of it). He told me it broke/ chipped and had to remove it. He reached the keyless by taking of the chronograph module. He usually works on it from the dial side but this was faster (thus cheaper).... so he said. Quote Link to comment Share on other sites More sharing options...
801run Posted February 22, 2009 Report Share Posted February 22, 2009 PS: I don't know why it happend, as I have removed and inserted the stem of a a7750 thousands of times... Hi Rolexman! Just a question on removing/reinserting the stem on an A7750, you seem to have done it a lot. When I reinsert the stem, I push the crown release button, I know on some movements you don't have to/should not use this button when you reinsert the stem. I havn't tried to reinsert it on the A7750 without using this button, what is your procedure here? Regards Quote Link to comment Share on other sites More sharing options...
marianetty Posted February 22, 2009 Report Share Posted February 22, 2009 for next time this might help hxxp://www.eta.ch/swisslab/7750/7750.html Quote Link to comment Share on other sites More sharing options...
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