Did you notice when the laptop was running could you hear the fan running . Often when a computer sits for long time if the fan was dirty it seizes up causing a thermal issue and the laptop shuts down.let the laptop cool down and restart it then listen for the fan . If you get no fan sounds try blowing air through the air ducts to get the fan to move then try starting it again once again listening for the fan . You may need to take the fan out and replace it if it doesn t work . Hope this helps