Fix Cooling Fan is Not Operating Correctly | System Fan 90b Error

Cooling fan is a essential component that eliminates excess heat from the system and make it cool. It
is common in computers that when you start it your cooling fan may spin faster and louder and eventually get an error code popped in your screen as, 

'' The System has detected that a cooling fan is not operating correctly '' 

To understand the root cause of this error we have to look at the hardware mechanism of how the cooling fan works. Generally there are three wires that gets connected into a Cooling fan, Red, Black and the Yellow wires. This Yellow wires controls the speed of the fan by receiving the instructions from the Basic Input Output System (BIOS) . When performing high end tasks such as Gaming, BIOS tells the Cooling fan to spin faster and when the computer is on idle the BIOS tells the Cooling fan to spin slower. Therefore it is normal to the cooling fan to stop spinning when it is not running any intense applications. 

The problem comes when the cooling fan finds it unable to remove excess heat from the system due to variety of causes. While you may continue to work with your computer ignoring this error message it is highly advisable to take measures to fix this as the Heat built up inside the system might cause potential damages to the internal components.

In this article we will discuss how to fix cooling fan is not operating correctly also known as system Fan 90b error. The methods used here will be applicable to all the laptop and desktop models out there including Hp models. 

Let's move to the topic,

1. Clean the Fan, Air Vent and the Thermal Paste

If you notice that the Cooling fan is spinning faster and louder than normal then there maybe dust and other particles clogged inside which makes them function less efficient. A cooling fan draws heats from the CPU and the other components and releases them out from the Air vents. Overtime dust and other particles from the surroundings can be accumulated inside it, therefore the fan has to do a harder job of eliminating excess heat from the system. Eventually due to this the system gets overheated and lead to this error type. So simply by cleaning it you can try to get rid of this problem. 

For doing this,

       1. Turn off your system and disassemble the components.
       2. Remove the dust with an Air compressor by giving a slight 
           blow to the fans.
       3. Then with a piece of cloth dipped in a Alcohol solution
           clean the Air Vents and the Thermal Paste.
       4. Now reassemble the components and turn on your system 
           and check whether the error pursuits.

2. Replace the Cooling Fan

In ageing computers the cooling fan may fail to work after the Manufacturer's warranty period. So with a dead fan the system may get overheated and shuts down automatically to avoid any further damages. You can physically check whether your cooling fans are running properly by keeping your ear near the Air vents, if you identify a noise produced by the fan then it is doing its job. If you don't hear any noise from the fan you have to a diagnostic test to check it further.

To do a Diagnostic check,

      1. Press the F12 key
      2. Select the diagnostic option (Then a test will be running 
          testing all the internal components)
      3. Select No. to perform a Memory test.
      4. Then press Custom test.
      5. Select the CPU fan from the device and perform the test.

If  you get an error message as, '' Fan the (processor fan)  fan failed to respond correctly '' , then the fan might be dead . Then the option might be replacing it with a new one. You can purchase a new cooling fan from a local shop or from a online shopping sites. Make sure to identify your current model of the fan before proceeding to purchase.

3. Run a Hard / Power Reset

Corrupted Thermal values in the memory will not only lead to hardware problems and glitches it can lead to this cooling fan error. By performing a Hard / Power reset basically you can remove all the power from the system and reset all the Thermal values on your memory.

To do a Hard Reset on a Laptop,

      1. Turn off your Laptop completely.
      2. Remove the battery and the power code.
      3. Disconnect all the peripheral components.
      4. Now press and hold the Power button for 10 to 15 seconds.
      5. Insert your Battery back to the Laptop.
      6. Turn on your computer and start Windows normally.
      7. Connect back all the peripheral devices.

Now you have successfully done a Hard reset for your system.

4. Run a BIOS Reset

Basic Input Output System (BIOS) is the part of the system which controls the Hardware components including the Cooling fan. Sometimes misconfigurations in the CMOS can stop the functioning of the Fan. By clearing the CMOS / Reseting the BIOS you can clear out the misconfigurations and reset back to the manufacturer's default settings.

 For Resetting the BIOS, 

      1. Turn on your computer.
      2. Press F2 / F8 / F10 / Del to enter setup (The key depends 
          on the model of your computer) 
      3. After the BIOS loads press F9 to run Setup defaults and 
           reset the BIOS.
      4. Then Press F10 to Save and Exit.

Now you have successfully Reset the BIOS back to the default settings.

About Mishal Roomi

by - Mishal Roomi on - August 10, 2019