How to diagnose failure of Ctrl-c, Ctrl-v, Ctrl-x ... (copy, paste, cut, ...) key combinations

I previously posted this to Ctrl keys not working properly - #4 by daggett

[I have a similar problem:] I can’t get Ctrl-C (copy), Ctrl-X (cut) or Ctrl-V (paste) to work.

As I have tried this on three different keyboards, this is clearly not due to a faulty keyboard.

I have also rebooted and run my computer with a Debian Linux root partition and still have the same problem.

So, it seems to me that the problem lies with the Central Processing Unit (CPU) or somewhere else on the motherboard. (If that is the case, I should be able to get this computer fixed or replaced under warranty.)

I have already searched for a solution with the following two sets of search terms:

linux how to diagnose keyboard problems


linux how to log input from keyboard

… and not had any luck.

Could anyone here please suggest to me how I could diagnose this problem?

Thank you for your attention.

A friend pointed out to me that, unlike with other keyboards, the ‘Fn’ key, rather that the ‘Ctrl’ Key, is at the bottom left of my keyboard. (The ‘Ctrl’ key is immediately adjacent to the ‘Fn’ key.) Whilst I had thought I was looking at the keyboard, when I attempted to press ‘Ctrl-C’, it now seems that I wasn’t.

Curiously, the other two keyboards, on which I had experienced the same problem, have the ‘Fn’ key at the bottom left hand corner. So, why I also experienced that same problem with those keyboards, for now, remains a mystery to me.