This guide explains how to access and clean the cooling fan in an Acer Aspire 3003LM laptop. Most likely this guide will work for many other Aspire laptops.
Does your laptop shut down without any reason? Does it feel hot on the bottom? Does the cooling fan work all the time and it’s very loud? If you answer yes on all three questions, most likely your laptop experience overheating.
After about a year or two of use, many laptops build up layers of fluff in the fan area that are thick enough to stop the flow of air. This means the CPU is not being cooled properly, it overheats, and the safety mechanism kicks in and shuts the computer down. You experience it as a reboot.
You can clean the fan and heatsink with compressed air. Buy a can of compressed air in a local home improvement store and spray it inside the cooling module until all dust is gone.