Welcome to Elbatrop1's Random Reboot Troubleshooting Guide.
Random reboots seem to plague computer builders/users frequently. I will describe some common causes of random reboots, as well as some ways to help fix/prevent them.
~This guide is intended for computers that arent being overclocked. If you are overclocking and dont know enough about diagnosing random reboots, shame on you
If anyone has anything to add to my list, please post below and I will add it. I know that this isnt complete, but these seem to be the most frequent causes of random reboots. Hopefully this gets stickied, as I'm sure it will help new and old members alike
When your CPU overheats, it will usually cause your computer to reboot. Video card overheating causes artifacts to appear on your screen, and usually wont cause reboots.
Enter BIOS upon powering on your computer. Most BIOs have a hardware monitor. Use this to check your temperatures and fan speeds.
There is also hardware monitoring software that can check your temperatures from Windows. Your hardware monitoring software should have come with your motherboard. If you have no monitoring software, you can go to www.cpuid.com
and get PC Wizard.
PC Wizard is an easy to use program that will let you know what kind of temperatures you have, and what your fan speeds are at.
CPU overheating is usually caused by a failing CPU fan or improperly applied thermal paste. Fortuneately, these 2 causes are easy to fix. If the CPU fan is dead, buy a new one and install it. If the thermal paste is improperly applied, remove the old paste off and apply new paste.
Power Supply (PSU) Problems
It is important to have a functioning, proper size of PSU for your computer. Having an underpowered or failing PSU is often the cause for random reboots. To get an estimate of how powerful a PSU, use this PSU calculator
and add about 50W to the minimum power the calculator gives you.
The easiest and best way to diagnose a faulty PSU is to swap it with another one that you know is in good working order. Because everyone doesnt always have an extra PSU around, this might not be practical. Other than swapping, the diagnosis of a faulty PSU might be because no other problems seem to be causing the random reboots.
PSUs just die after a while. Just like most electrical components, they age and die. Often, a PSU will make a loud noise, or let out some smoke. Sometimes, though, the PSU will die silently. Sometimes the PSU will die due to overheating because its fan died.
Faulty RAM and RAM slots can cause random errors/reboots.
The best way to determine if RAM is your problem is to run your computer with one stick at a time, and see if the problem occurs for either stick. This obviously doesnt apply if you only have one stick to begin with
Also, try the RAM in different slots. The actual slots might be causing RAM-failing like problems. The next step is to run memtest86
to determine if you have faulty RAM.
Sometimes RAM is just faulty. Either it makes it past quality control at the manufacturer or it gets damaged during shipping. Because most Memory manufacturers have lifetime warrenties on their products, either return the RAM to the retailer that you purchased it from or return the defective product to the manufacturer.
Viruses, Spyware, etc can cause problems that resemble that of hardware problems.
When none of the hardware causes seem to be causing the random reboots, there is a good chance that it is software related. Of course, software problems should be the first thing to check, because it is least inexpensive because you dont have to buy anything to replace faulty components. To prevent or fix, make sure you use a software or hardware firewall and an updated virus scanner and spyware scanner. Go to the TF Freeware Utilities List
to get such things if you dont already have them.
Viruses, etc can come from a variety of places. Often, viruses will show up because of irresponsible web surfing or downloading, as well as pirated software.
Hopefully that helps some Random Rebooters