7750 date change at midnight

[xlr8tn]

My A7750 has an issue where the date does not change at midnight or any time other than thru the quick-set.  I recently disassembled it and put it back together and could have messed something up, but that was the problem I initially started with.  Is there a trick to install the driver wheels?  I took off the dial again to watch the action while setting the time and when it gets to midnight, the little arrow hand pushes against the metal pin, but just sits there and does not click to the next date.  Anyone run into this before?

 

Thanks,

Brent

 

 

[Motoman4540]

I was going to post a similar question. My brand new AP A7750 will advance the date with the quick-set and when I advance the hands manually, but will not change the date just by running . . . Is this a simple issue or a big issue to fix? I am not sure of the mechanism, but maybe whatever changes the datewheel needs a little too much pressure for the watch to supply itself, which might explain why it changes when I advance it manually . . .?

[FxrAndy]

I would suggest that this is an issue created by badly fitted date or day wheels and the inability of the Chinese to fit the retaining washer that holds the day wheel in place, proper refitting should solve it twinned with a service maybe

[xlr8tn]

Andy,

I disassembled the top side and replaced the day star driving wheel and the date indicator driving wheel.  I am guessing that the red dashed line on the 7750 website is the alignment of pin on top of the wheel.  I re-assembled up to the date wheel and left off the day wheel to see what was going on.  With my watch in time setting mode, I wound until the brass pointer on top of the indicator wheel was resting on the pin and pressing against the date wheel tooth.  But not matter how much I wind at this point, it never snaps to the next date.  If I use my tweezers and compress the date jumper away from the date wheel, it will change date.  My guess is that the jumpers spring is too strong to allow the date to move, however, in date setting mode, it changes normally.  Any thing else I should try?

 

-Brent