put the laptop down and walk away slowly. very slowly. do not turn your back on it or let it loose at night when the lights are out.
the keyboard is not shorting, your motherboard is not fried or disconnecting, it has been taken over by demons. the symptoms you have experienced with the emphasis on the #3 is a possession of the worst kind.
stock up on inscence, bay leaves, phosphorous and sulfur powder, kosher salt and fresh goat or chicken blood. On Wednesday morning, call the montel williams show and have sylvia brown walk you through the exorcism procedures. after the ceremony has been completed you will not have to worry about continuous hauntings.
then promptly head to future shop, best buy, london drugs or which ever computer store tickles your fancy and get a new one.