Toshiba keyboard not working

I cannot make head nor tail of Toshiba site to get help and googling has not helped me find out what has suddenly (overnight) stopped keyboard working on Toshiba Satellite L500 1-XM laptop.

I can use USB keyboard (not ideal) and a new replacement keyboard did not work.

Can anyone make any suggestions on how to solve the problem?

This is not urgent but it is nice to have a working laptop.


Thanks in anticipation.