Computer crashed when cpu became overheated. Took cover off discovered fan not spinning . Fan started spinning happily when I gave it a slight nudge with a pencil, computer runs happily provided I do this. What's ther answer guys, new fan? It's a bit of an odd shape, I am finding it difficult to get a similar one, it's 70mm across (fan blades 65mm across). I am a total novice at this game, any ideas anyone. UN