You need to figure out whether it's a hardware or software problem.
Have you tried unplugging the keyboard and mouse and plugging them back in?
But, I suspect software.
Will it boot from floppies? Is the keyboard OK then? If so, try using a backed-up version of your .INI files. And try running Henk's WPTOOLs on the INI files (if they're compatible with ECS).
That's about all I can think of. :-(
HTH.
Cheers,
Scott.