how can i get the keyboad of my sam4s register reset?

Oh dear. NEVER use water on the keyboard. I always use methylated spirits to clean any part of the register as it evaporates and can't cause problems. You need to take the keyboard apart and dry out the keyboard membrane inside. you must pull the layers of the membrane apart (carefully, it can tear) so that you can dry the little carbon dots that sit under each key. Otherwise, take to a dealer

Registerman
June 2011