HP-41C - Memory lost

[Vintage63]

Hello everybody!!
My calculator throws a 'memory lost' every time I move it without being careful.
Today I picked it up and in doing so banged it against my monitor, memory lost.
Miscalculated the distance between the two.
If I put it down with a slight 'bang' it doesn't switch on again unless I deliberately bang it on the desk and remove the batteries multiple times.

This is really annoying. I've had enough of reprogramming it every time.

How could I solve this problem once and for all? I don't want to be experimenting every trick in the book.

Thank you
Marco