This guide explains how you can clean or replace cooling fans on Toshiba Satellite A70 and A75 series laptops. In this model the cooling fan is buried deep inside the laptop, there is no easy access from the bottom. In order to access the fan assembly you’ll have to disassemble the laptop and remove the motherboard. This guide is not for beginners.
Toshiba Satellite A70/A75 has two fans. Both fans are mounted in the same cooling assembly and if one of the fans stopped working or it’s noisy, you’ll have to remove the whole fan assembly. You can find a new one if you google for this part number K000016310 or just buy it here.
This model has a known problem with the cooling system. Dust and dirt easily gets trapped between the fans and the heat sink, as a result of that, the laptop overheats.

Here’s another laptop disassembly guide for Satellite A70/A75 series.
Before you disassemble the laptop, try cleaning cooling fans with compressed air.