My laptop was making a strange rattling noise. I took it apart to try and fix the trouble.
It was the slide bearing for the main fan that had gone dry and was wobbling. Adding new bearing grease fixed the problem.
This was 4 years ago and now the noise had started again. So I made a Youtube video showing how to disassemble the laptop and grease the fan. After applying grease the noise stopped.
Step 1: Remove the back panel covering the fan and disconnect the cable.
Step 2: Unscrew the fan from the panel.
Step 3: Open the fan by undoing 4 screws.
Step 4: Remove the fan rotor from the housing by lifting it straight up.
Step 5: Apply a small amount of bearing grease in the axle hole.
Step 6: Reassemble the parts in reverse order.