Try entering the bios first to see if their is a diagnostic tool to detect faulty Hard ware.
I assume the fan just fried and died, so you are going to have to replace the heatsink/fan.
This takes a bit of skill and mechanical ability. Assuming a faulty fan You will have to:
1. get a replacement fan/heatsink for your laptop
2. take the old heatsink/fan off
3. put the new heatsink/fan on.
Unless you've taken apart and repaired a few laptops i strongly advise you to take it to a repair shop.
Laptops are a pita to work on and like one poster mentioned it's extremely easy to cause additional damage.