First check if the fan has a lot of dust in the laptop. This can stop it from spinning. If this is not the case and there is nothing that is blocking the fan, then it could have been short circuited somehow. If that is the case then replace the fans and it should be ok. If it doesn't improve then there is something wrong with the motherboard. This assumes you have all the drivers up to date and that the laptop doesn't overheat while gaming.