One day, my laptop did produce a rattling sound that is coming from the fan, like the blades are hitting something. so i have decided to open and look at it. i found out that one of the blades of the fan was broken and i think that this is the one causing the sound. then i reassembled the laptop, but now the fan is vibrating abnormally and differently than the way it used to work before. should i buy a new fan? thank you.