There is something really weird going on - I can't write in my password
in the terminal when prompted, this is what happened, I wrote
xxxxxxx@xxxxxxxx-laptop:~$ sudo dpkg --configure -a (hit return and was
prompted for my password as below)
[sudo] password for xxxxxxxxx: (not looking at the screen I typed in my
password and hit return and got)
Sorry, try again.
[sudo] password for xxxxxxxxx: (this time I watched the screen and
whilst typing my password nothing happened, hit return again)
Sorry, try again.
[sudo] password for xxxxxxxxx: (all I get is the blinking black cursor,
no input from the keyboard).

So I am stuck again without being closer to solving the original
problem................