Skip to content
SOS Informatique Computer repair in Lyon - Individuals and businesses

My computer is hot and noisy : what should I do ?

A fan blowing hard is not the fault : it is the symptom. The machine is fighting heat it can no longer get rid of.

And that fight has a visible cost : beyond a certain temperature, the processor deliberately slows itself down to survive. That is why overheating and slowness almost always come together - the machine is not dragging because it is old, it is dragging because it is too hot.

What happens inside

The heat produced by the processor passes to a heatsink through thermal paste, then out through a fan across very fine fins. Three things can fail : the fins clog with dust, the paste dries and stops conducting, the fan wears and spins more slowly. All three happen with time, and often together.

The unmistakable signs

  • The fan speeds up as soon as you open a video or a video call, and never comes back down.
  • The underside of the laptop becomes hot, and so does the area above the keyboard.
  • The machine slows after twenty minutes of use, then returns to normal after a break.
  • It shuts down abruptly under load - see PC switching itself off.

What you can do yourself

  • Clear the vents. A laptop resting on a bed, a sofa or a duvet blocks its air intakes within seconds. A hard, flat surface is enough to change things.
  • Blow dry air into the grilles, with the machine off and unplugged, in short bursts. Hold the fan still with something thin while you do it : spinning it at high speed with compressed air can damage it.
  • Check what is running. A process consuming constantly heats the machine for no good reason. Task Manager, sorted by processor use, shows it in seconds.
  • Let a desktop breathe: ten centimetres behind the tower, and no closed cabinet.

The limits of compressed air

Blowing from outside moves the surface dust, but the real problem is elsewhere : a compact mat forms between the fan and the heatsink fins, in a place no jet of air reaches without dismantling. On a machine over three years old that is genuinely running hot, cleaning from outside buys only a few weeks.

What belongs in the workshop

A full clean means opening the machine, removing the fan and heatsink assembly, taking out the mat of dust and replacing the thermal paste. On a device more than five years old that paste has invariably dried out : replacing it often drops temperatures by fifteen to twenty-five degrees.

A fan that squeaks, clicks or vibrates is near the end of its life and can be replaced - an inexpensive part, provided you act before it stops altogether.

Why not to let it drift

A machine that runs permanently hot ages fast : components cope badly with repeated heat cycles, the battery degrades more quickly, and the drive does not appreciate it either. A service every two or three years costs a fraction of an early replacement.

Having the machine serviced

We record temperatures under load before and after the work, which lets you measure the result rather than assume it. Cleaning and thermal paste are handled through a workshop drop-off, in Lyon.

Frequently asked questions

How often should a computer be dusted out ?

Every two to three years in domestic use. Far more often with pets, tobacco, or in a dusty workplace : hair and particles clog heatsinks very quickly.

Is a cooling stand for a laptop useful ?

It gains a few degrees, especially in summer. It is only a supplement though : if the internal fins are blocked, no external fan will make up for it.

The fan runs hard but the machine stays cool, is that normal ?

That happens when a program is working the processor in the background, or after a changed power setting. Look at what is running before concluding there is a hardware problem.

Further reading

Would you rather we took care of it ? See our laptop repair service, in Lyon and across the Rhone.

A machine that is hot and loud ?

Full clean with temperature readings before and after.

Contact Us