With so much going on inside a computer case, computer fans are a vital component in ensuring the machine continues to function well. Components heat up quickly inside a computer tower, and a series of fans and assorted other cooling devices are the only things keeping the machine from overheating and eventually malfunctioning. When a fan becomes faulty, it often exhibits signs that make it clear to the user that something is wrong.
Computer fans are designed to run quietly in the background, allowing them to complete their tasks without providing much of a disturbance to the user. When a fan becomes faulty, it will occasionally begin operating more loudly, either with a rattling sound or an audible hum. These sounds don't necessarily mean that the fan is failing. It is possibly the sound of something that has become lodged in the fan or that the fan has come loose. Taking the computer to a professional is the best course of action the moment a fan becomes noisier. It is also important to note that fans are usually designed to function with more intensity when a computer starts up or shuts down. More audible sounds from the fans are expected in these instances.
A fan's primary role is to ensure that a computer's components don't overheat during use, which could result in permanent damage to the machine. When a fan breaks down, the computer's performance often serves as the most telling sign. Overheating computers exhibit several symptoms, the most common of which is a loss of function through repeated freezes or lockups. Other signs include general protection failure messages and a malfunctioning hard drive that eventually leads to the "blue screen of death," the term given to an error message signaling a major hardware failure. If the user opens the computer case and these problems subside, overheating is the most likely problem and the faulty fan requires replacement.
Certain newer computers are equipped with systems that can detect a malfunctioning fan before it reaches the point of sounding like a jet engine. These computers give out warning messages like "CPU 1 fan failure" or "Power supply fan failure," along with a notification that the computer will shut down if the problem is not dealt with in one minute. These messages are triggered by the failure of the fans themselves, so a user will know right away if the devices are faulty. In this case, taking the machine to a professional is the best decision unless the user knows how to safely and effectively replace the fans himself.