Fan Trouble!

Hello all was hoping someone can help me out with a problem im having.

I have a acer aspire 4315, had it for about 18 months no real trouble, however last time I booted it up the fan got power started to spin for about half a second then went off.

The laptop still boots to windows, but on boot it would usually do a big spin up for about a 2 secs then slow to medium speed. I have not had the guts to get into windows and install a temp monitor program as I think without a fan the celery with just blow its self away after about 2 minutes.

I have had a look inside and cant see anything majorly wrong as my 1st guess was that it was some kind of short, the fact that the fan does spin for a little while would suggest that it still works but for some reason it will not stay on. Was looking for the thermal sensor but didnt really have much luck with that either as I thought it may have moved.

Anyways any help would be appriceated.

 

bump bump**

 

Dooes anyone know if the heatsink and fan unit from a 5315 would fit in a 4315, probs only need the fan but might just get full unit from ebay.