What a CPU (Processor) Does When it Goes Bad or Is Failing
The CPU is the brains of your computer. When your computer's CPU is getting older, is used to do functions for which it wasn't intended, or overheats due to poor power flow, it could fail completely.
Here's how to determine what's causing your CPU to fail and what the problem means. We will discuss how to use a basic approach to determine the problem as well as some other issues that may be involved as well.
This process can be a long and expensive process of elimination. Hopefully this article will help you get to the source and save you time and money in the end.
Common Reasons Why a CPU Goes Bad
The most common reasons for CPU's to go bad are simple:
1. Age. Every machine has its limits. A computer that is five years old or older is considered to be in its grace years. They can just give up.
2. Heat. Overheating CPU's lead to a dead CPU. This can happen when room temperature is often above 80 degrees Fahrenheit and if the computer has an ineffective cooling mechanism inside.
3. Overclocking or Stress. Not all CPU's are created equal. Don't make a dual-core do what an eight-core is intended for. Overclocking has its place, but be careful to be realistic. Also, if a game says it needs a certain minimum to run, don't run it on an under-clocked CPU. The same goes for software for video or photo editing. If you want to over-stress your processor this way, by all means go for it, but otherwise upgrade.
4. Electrical Power Surge. Whether it was the power supply going bad or lightning, any high voltage spike can render a CPU useless. Be sure to have a surge protector and a battery backup attached to your computer to help prevent this sort of thing from happening.
The Simple Approach to Finding the Problem
Uninterruptible Power Supply
This article's first photo shows what can happen to a CPU capacitor when the power flow isn't consistent. Protect your machine by attaching it to an uninterruptible power supply. If there is a power spike, your computer will be protected.
Common Failure Symptoms
CPU's often simply burn out. To determine that is your problem, consult this list of common processor failure symptoms:
- Computer turns on, no beeps, no screen. Does not POST (Power-On Self Test)
- Computer turns on, fans run at highest speeds, still no POST, and operating system not loading.
- Computer powers on, but turns off immediately.
- In Windows (or any other OS), screen freezes after being on for a few minutes. In some cases, the screen may freeze during the load screen of the OS (a.k.a. the Windows logo screen).
- System halt errors (famously known as blue screen of death) that calls out the processor as an issue.
Eliminating False Positives
There are other components besides the CPU that can create the above symptoms. This can lead your diagnostics astray.
Below are some simple things to look for that can cause the same symptoms. Once they are eliminated, you may have a bad processor. Otherwise, you have found the real source of the problem.
1. Heat. Next to dust, heat is the number one processor killer. Most CPUs run from 30 degrees Celsius to 50 Celsius. If your machine is not cooling well, then there is an issue. CPUs above 70 degrees Celsius are in the danger zone. Between 80-85 Celsius is the melting point. Check the heat-sink in your computer and make sure it is clear of dust and obstructions. Make sure the fan on the heat-sink is moving smoothly (3,000 rpm is average +/-.) If the fan and heat-sink are fine, then the thermal compound may be old and dried up. Replace the thermal compound. The thermal compound should be applied evenly, about one mil thick. (Note: System temperatures can be viewed within the system BIOS or by using a utility to monitor the CPU settings.) If you are going to replace the thermal compound, I strongly recommend Arctic Silver 5.
2. Capacitors. Look for any bulging or leaking capacitors on the motherboard near the CPU or memory areas. If there are any bulging or leaking capacitors, this creates voltage irregularities, thus system errors.
3. Power Supply. Much like bad capacitors, bad power supplies can create all kinds of strange voltage and amperage irregularities. Check the power supply with a tester to see if it is in good health.
4. Video Card. If your system has a dedicated video card, check its capacitors and fan as well. Video cards can freeze a system, in the same way a CPU can. They can also keep a computer from POSTing.
Video Card Bad Capacitors
After Checking Everything
If all the above checks out well, then you are looking at a bad CPU and maybe motherboard. This is especially true if all the fans and lights are on but "nobody is home" when the computer is turned on.
At this point, the only way to clearly diagnose the CPU/motherboard is to get a working CPU and replace it. If all goes well, then the CPU was bad. Otherwise, it was the motherboard or both.
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© 2013 Ryan Hutzel
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