In this lab you replace the thermal paste on an LGA1700 processor with its stock cooler: you remove the cooler, clean both contact surfaces with isopropyl alcohol and apply new paste.
Starting point: the motherboard is assembled as it is at the end of the motherboard assembly lab.
What thermal paste is for
The surfaces of the processor and the cooler base look smooth, but they have tiny imperfections. The paste fills those gaps, which would otherwise hold air, a poor heat conductor, so heat passes better from the processor to the cooler.
How often to replace it
There is no fixed interval: it depends on the paste, how the computer is used and how hot it runs. As a guide, in a desktop computer with normal use it is usually checked every 2 to 4 years. It must also be replaced whenever the cooler is removed, even briefly: the old layer never seats properly again.
Signs it is time to replace it
- The processor runs hotter than before under the same use.
- The fan speeds up and gets noisy more often.
- The computer slows down when it heats up (the processor lowers its speed to protect itself).
- It shuts down or restarts by itself under heavy load.
Why it wears out
With repeated heating and cooling, the paste dries out, cracks or is pushed towards the edges. It then leaves gaps and conducts heat less well.
Materials
- Lint-free wipes, so no fibres are left between the surfaces.
- Isopropyl alcohol of 90% or more, which dissolves the paste and evaporates without residue.
- New thermal paste in a syringe.
Types of thermal paste
For a normal computer, a paste that does not conduct electricity, such as ceramic or carbon-based paste, is enough. Liquid metal cools better, but it conducts electricity and corrodes aluminium: a drop on the motherboard can damage it, so it is only for advanced users.
Before you start
Work with the computer switched off, unplugged and cool, wearing a grounded anti-static wrist strap. If the cooler is stuck hard, do not yank it: you could pull the processor out of the socket.
On laptops the process is more delicate and varies by model: check the manufacturer's guide first.
Lab steps
- Remove the CPU cooler
- Clean the processor
- Clean the cooler base
- Apply new paste
- Refit the CPU cooler
