Why Laptop Fan Is Not Working

As you use your laptop and go about your business, a sudden message declaring a problem with your cooling system could put a quick and sudden end to your work. This message usually appears when your laptop fan isn’t working properly, leaving your machine vulnerable to overheating.

In most cases, your laptop shuts down shortly after alerting you to your cooling problem, effectively putting an end to your ability to keep using it.

The Dangers of Laptop Overheating

Heat is a dangerous enemy to computers, and your laptop’s slim design and tightly packed components make it especially vulnerable to overheating. Every component inside your machine generates heat during operation, and if not properly vented, this heat can build and cause damage.

 The delicate transistors and computer electronics can warp under extreme temperatures, causing operational problems and even physical damage. If left unattended, an overheating laptop can completely fail, rendering it dead and unusable.

Laptop Fan Failure

One of the most common causes of the “cooling system” message is a malfunctioning cooling fan. Your laptop fan could stop working if it becomes too clogged with dust, or suffers damage from an accidental drop. If you receive the message shortly after your laptop received a nasty spill, the fan may require replacement.

Collected dirt, dust and lint inside your machine can essentially choke your fan to death. Use some canned air to blow dust out through the air vents. If you’re comfortable with taking your machine apart, you can give your internal components a more thorough cleaning.

Dried Thermal Paste

Slathered between your heat sink — the cooling fan that sits atop your CPU — and your processor is a layer of thermal paste, which helps whisk away the chip’s heat. If this paste dries up, your laptop can overheat, even if your fan still works perfectly.

You can replace this paste yourself by taking your laptop apart, wiping the dried paste off with some rubbing alcohol and reapplying a new layer. Fresh paste and a good cleaning while you’re in your machine can help keep it running cool.

A Helping Hand

Sometimes even a working fan, fresh thermal paste and a clean interior won’t help keep your laptop cool. To help encourage a cool system, keep all of the air vents unblocked to allow proper airflow. Add a cooling pad — a stand with additional fans — to help whisk away more heat and keep your laptop running and functioning properly.

Laptop Won’t Start After Cleaning Fan

The buildup of dust inside your laptop can block air circulation and damage your laptops delicate components. Regular cleaning helps keep your computer running efficiently for longer periods of time. If your system won’t boot after a cleaning, it could be as simple as a loose cable or as serious as damaged hardware.

Thermal Paste

In most cases, cleaning your internal cooling fans shouldn’t cause much in the way of problems, but if you cleaned your CPU fan — also known as the heat sink — you may need to replace the thermal paste. This substance sits between the heat sink and the CPU, acting as an additional heat-whacking guard against overheating.

Removing the heat sink to clean it may have wiped off some of this paste, or the paste may have dried up if your computer is a few years old. Without an adequate layer of this goo, your CPU would overheat quickly, so your computer may not start to prevent damage to the processor. Replace this paste and see if that solves your booting problem.

Loose Cables or Hardware

In the process of opening the case to get to your fans, you may have knocked something else loose. If your computer can’t verify a good connection with the various components, it can’t communicate with them to boot up properly. Verify that all cables and components are connected tightly and securely.

Don’t just look — unhook and rehook cables, remove and reseat RAM and cards. Look inside your entire case, not just where you think you touched before. Make sure everything is connected properly, then boot your computer again.

Hidden Dust Bunnies

A wayward dust bunny or two may have escaped the Great Cleaning and hidden under another component. This can have an effect similar to a loose connection, as it can prevent proper communication between all the various components.

Perform another cleaning — armed with canned air, cotton swabs and rubbing alcohol — but this time remove all components to make sure that there are no hidden dust bunnies to cause problems.

Static Shock

Electro-static discharge (ESD) is a destroyer of computer components with a single touch. If you happened to touch your video card or CPU while you were cleaning and felt the familiar zap of a static charge, you may have inadvertently killed that component. Using a static-creating cleaning object, such as a dry brush, can generate a charge without your knowledge.

Touching another component can discharge this electricity unnoticed, delivering a possible death blow to your computer. Seek the help of an experienced technician to test your components for signs of life.

How Do I Make Sure My Laptop Fan Works?

Laptop fans expel air and make a soft to moderate audible sound under normal use. If your laptop’s fan is silent, the air near the vents is calm and the laptop is very hot, it’s likely that the fan is not working.

Laptop cooling fans play a crucial role in laptop longevity and functionality, and an overheated system doesn’t work well, if it works at all. Make sure to replace a broken fan immediately to prevent hardware failure.

Listen for Noise

A properly functioning laptop fan sounds like a soft propeller fan; however, the fan may not be audible when you first turn the computer on, because it is running at its slowest possible speed.

To provide more airflow and cool the system, the fan speeds up as you continue to use your laptop – it will likely switch to a faster, louder mode after about five minutes, when your laptop reaches its operating temperature.

The best-cooled laptops may have incredibly quiet fans that are only audible in silent rooms by careful listeners. Note that your fan may be broken or obstructed if it makes irregular pulsating or loud screeching noises.

Feel for Air

Even if you can’t hear the fan working, you should be able to feel the air coming out of the vents. The airflow may be very light when you first turn the computer on, but it picks up once the system reaches its normal operating temperature, at which point the laptop fan should start expelling air from the main exhaust vent, usually located on one of the laptop’s sides.

Put your hand, palm-facing the system, about half an inch away from the vent and feel for airflow. If the laptop is silent and there’s no airflow, the fan maybe broken.

If you can hear the fan working hard, but only feel gentle airflow from the vents, the fan may be obstructed, in which case clear the vents with a compressed air blast.

Watch for Errors

If the computer regularly restarts without warning, slows down to a halt in normal use or gives you the dreaded BSoD, or Blue Screen of Death, there may be a problem with the fan. The fan itself is attached to a heatsink as part of the cooling unit, so even if the fan is blowing air, there can be a problem with another part of the unit.

Your system may overheat if the cooling unit comes loose or the thermal compound that bridges the CPU and the cooling unit wears out.

Check the Temperature

Even if the fan is expelling some air from the vents, it may still have a hardware problem, such as a motor issue, that prevents it from cooling your computer sufficiently. Some laptops display a temperature reading when you turn them on, but if yours doesn’t, use a hardware monitor program to check the CPU’s temperature (see Resources).

If the program registers a constant temperature of over 160 degrees Fahrenheit when your laptop is doing absolutely nothing, the fan may be broken.