Every key on the standard keyboard handles over thousand of strokes - without making a mistake. Despite this fact, keyboards can start acting up but this is mainly because of external sources: Dust, crumbs, hair, cigarette ash, liquids and so on, which often falls into the spaces between the keys of the keyboard over the course of time. All these things affect the mechanics and can cause contact issues. If the keyboard is not working properly and it is not due to a drained battery and pinched or broken cable then the first you should do is shut down the computer and turnover the keyboard once and shake it vigorously so that the rough and loose particles will fall out. The next step is to clean it with a vacuum cleaner and upholstery nozzle. A possible film of dirt on the keys and frames can be removed with the normal wet wipes.