if you have a friend that has a volt meter then test to see if the ac brick has any output. the output is stamped on the brick in dv volts. most time between 12-17v dc. if the brick wires are twisted or kinked..that most lilky the failure point. laptop also fail if the rubber o-ring on the brick tip falls off and the brick shorts out the laptop mb or the pin on the mb breaks off or the soilder joint snaps.