help 5140.....i'm disperate...

Hello to everybody... I have a problem with a 5140, this one day begin to restart on shut off by himself, then after 2 day totally shut off and never come one again. i sent to service in warranty (totally idiot...) and thay said that the problem was tha board due to a shock.... but the problem happen on a table and this were never subject to fall or damage.... So i'm here to ask if it could be a micro or hw failure? is it possible fix it? only because this is a gift very important for me.... really thank you...