Power On Self Test

If your computer beeps irregularly when the computer is turned on, or turns on but does not boot, you may be experiencing a problem with the Power On Self Test (POST).

If you are getting a beep code sequence such as one long beep and two short beeps you may want to have a look at our beep code page to see if your beep code is listed there.

Finally, if you reboot the computer several times and it sometimes starts up you may want to read this article - PC restarts many times and then boots up.

Power On Self Test (POST) problems can be caused by any of the following situations.

• New hardware conflicting with old hardware.
• Bad or failing hardware device.
• Other hardware issues.

Before you carry out any work on your computer make sure you protect your PC's delicate circuits from static electric charges on your body by properly grounding yourself. If you don't have a grounding strap at least ground your body by touching the metal part on the outside of your PC's case before touching the inside of your PC or any component, including the motherboard.

New hardware conflicting with old hardware

If any new hardware has just been added to the computer, remove that hardware to make sure it is not the cause of your problem. If after removing this new hardware your computer works, it's likely the computer is either not compatible with the new hardware or a system setting needs to be changed to work with the new hardware device.

Bad or failing hardware device

Remove everything from the back of the computer except the power cable. Turn on the computer and see if it beeps normally. If the computer has never beeped also connect a monitor to the computer to see if a message occurs.

If you are receiving a sequence of beeps see our beep code page for a listing of all the different beep codes and what they mean. These beep codes can help you to identify exactly what computer component is failing or is dead.

Make sure all the PC's fans are running. If a fan has failed (especially the heat sink fan for the CPU) your computer could be overheating which can cause it not to boot.

If you were unable to determine by the beep code what component is failing, or do not have a beep code, disconnect the cables from the CD-ROM, DVD-ROM, Hard Drive and Floppy drive and from the Motherboard connectors. If this resolves your irregular POST, attempt to connect each device one at a time to determine which device and or cable is causing the problem.

Check your Hardware Components

Hardware problems, such as bad memory or a malfunctioning CPU are another major cause of computer errors.  For example, the ikernel.exe application error may occur if there is a problem with the memory. To check your hardware on a regular basis you may use a good hardware diagnostics tool. If you are using Windows Vista, you may use the memory diagnostics tool that is included with the operating system to check the memory chips on your PC.

Clean your Registry

Computer errors can also occur due to a large, bloated and unstable registry that is full of unwanted and corrupt entries. To prevent these problems, you must regularly scan and clean your PC with an efficient and trustworthy registry cleaner tool.

NOTE:: QBS PC Help recommend several tools to help keep the Windows registry and your whole PC in tip-top condition - click here to find out more.