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How to Test a Faulty CPU

written by: Steve McFarlane•edited by: M.S. Smith•updated: 5/9/2011

Identifying a defective, overheating or dead CPU can be difficult? Here is a guide on how to identify symptoms of a faulty cpu.

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    Without the CPU working there is no hope of much else happening on a computer. While some of the symptoms of a faulty CPU can be caused by the failure of other components, the symptoms that we outline below are good indicators that the CPU is malfunctioning, failing or dead.

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    Unusual Fan Sounds and CPU Overheating

    Moving parts are usually the first to fail on a computer. This is usually true of computer fans, of which there are usually two in most machines: How do I know if my cpu is overheating one for the power supply and another for the CPU. A sign that your computer’s CPU fan is failing is a change in the sounds that it normally makes.

    If the fan starts to make wining, clunking or groaning sounds, it is a sign that the fan is coming to the end of its days. Once the fan stops working properly the CPU will not get the cooling it needs and will start to malfunction. So, we can say that a dying fan is a sign that your CPU will soon start malfunctioning.

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    Blue Screens & OS Error Messages

    Another sign of a defective or overheating CPU are constant blue screens and Windows error messages. If the CPU is not being cooled properly the computer may still boot-up, but soon after will start having problems. The computer will usually freeze and then display a blue screen or some other Windows error message.

    Fortunately, fixing the overheating problem may be as easy as reapplying thermal gel or replacing the CPU fan. Thermal gel helps the CPU transfer heat from itself to the heat sink but the thermal gel can become hard with the passage of time, though it usually takes years for this to happen. You will need to remove the heat sink and reapply the thermal gel.

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    The PC Randomly Shuts Itself off or Freezes Randomly

    A CPU may work normally until more processor intensive tasks are undertaken such as intense game play, photo editing and video editing. While this could also be a sign that the CPU is overheating, a computer that restarts randomly when it is put through its paces could indicate that something is wrong with the CPU.

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    Signs of a Dead CPU – The Computer Fails to Power-up

    Owing to the fact that the CPU is the brain of the computer, scarcely anything will work if the CPU is dead. Signs that the central processing unit is dead or dying is a computer that doesn’t respond when the power button is pressed. The fans may spin up, but the computer won't boot.

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    High Frequency Beeps – Beep Codes

    Faulty cpu chip symptoms 

    Another sign that something is wrong with the CPU is the sounding, by the computer, of sequenced beep codes or audio alerts. If the computer makes repeated high/low beeps as well as high frequency beeps while the computer is running or just when it is turned, the CPU may need to be checked. BIOS or motherboard beep codes are designed to diagnose hardware or configuration faults. Check the motherboard’s manual or the manufacturer’s website to decipher what the beep codes mean in order to determine what is actually wrong.

    While a failing CPU is not the only thing that can cause a computer to randomly restart, given blue screen error messages or even high frequency beep codes, these are usually a symptom that something is wrong with the central processing unit.

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    Image credits:

    Faulty CPU chip symptoms,"

    “How do I know if my cpu is overheating,"