Hello Gary.
Yes, unfortunately I do tend to whack keyboards pretty hard.
As you said, it's because of the many years of piano playing.
Thanks to the advice of many members here, especially Chris ( OverOver ) and Snicker,
I have opened up the Genos and reinstalled the offending key, which had jumped from it's
insert joint.
The bar holding the key in place was a little bit loose, so I assume that it might be the cause,
though I wonder why other keys did not jump out of their sockets, if that were the case.
I did find other screws that were slightly loose, both in front and under the keyboard as well
as the bars holding the keys in place, which I tightened.
I did not touch the circuit boards or anything else.
I transport my Genos 6 days a week and like many things, including cars, furniture etc,
I suppose that screws probably have to be tightened again after a period of use.
That is my theory anyway. All in all, happy days are here again.
Thank you all for your help and comments.
Best Regards,
Abby.