i have an ancient Toshiba Satellite L310 PSME6L 00K001

other parts are working but mobo is (DEAD)
two shops said the mobo is dead.. but 1 shop said only the fan
my problem is that my laptop will get overheat so fast
cuz the fan only function for few minutes then laptop suddenly go off

should i buy new mobo or new laptop?
or
should i trade in with shop that buy faulty laptop?
or
anyone interested to buy as spare parts?

specs are:

ram: 2gb
screen: lcd 1024x768 not sure about the size
procs: dual core 2.16ghz (gma 4500m)
storage: - (want to keep)