I started by removing the components that were easily accessible: Hard drive, Modem, RAM, DVD drive and the battery. I then removed all the screws from the bottom of the laptop and carefully placed them aside. Laptop screws care extremely fiddly and tiny: one size does not fit all. If they get mixed up you could spend hours trying to figure out which screws go where. I was then able to remove the keyboard and disconnect all the cables and top case screws.
I then carefully un-clicked the plastic snaps and was able to remove the top case to get in the laptop
With the top case removed I was able to remove the motherboard and get to the fan. There we found the culprit:
Up against the heat sink and heat pipe was a carpet of dust that was obstructing airflow. With that removed it was just a question of reversing the previous steps to get the laptop in one piece. The laptop started up without issue and was running much cooler afterward.
One of the biggest issues with laptops is that they are designed to be as compact as possible with not much regard to maintenance and access. While Laptops have been getting better in this aspect in respect to hard drives and RAM, the processor is often forgotten. This is harmful to the average consumer that can not diagnose such issues, they end up paying hundreds for a job that requires few tools and parts but a lot of experience.
It is a major design flaw which could be engineered around, yet very few manufacturers bother.
