I recently bought this model of Certina DS Chronolympic LCD quartz from 1977, Reference 787 1420 41, Calibre Certina 787, ESA 934 712:
Very nice watch but unfortunatelly none of the buttons are responding from my input.
I have a lot of experience of trial and error of my other watches, but this one really beats me!
Does anyone have any tips & tricks or even a manual for this one? Have searched through entire internet I think without finding one.
Regards / Stefan