Samsung SR-L629EV fridge/freezer?

I have a Samsung SR-L629EV Fridge/Freezer.
the Freezer part has stopped working. The temp reading on the door is correct (ie room temp) but the fan is'nt running to make it cool down. I have looked at the fan and it spins freely when i rotated it by hand. It can be on for a few minites and then trips out the electricity,the fridge part is working fine. The fridge/freezer is about 6 years old.
Can anyone help.