CMOS Checksum Error

CMOS Checksum Error

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Note: Includes Checksum Error – Defaults Loaded and Checksum Failed

Explanation: A checksum is an error-detecting code containing a numerical verification used to compare the BIOS settings stored in the CMOS memory. Each time the system is started this number is recomputed and checked against the stored value. If they do not match, an error message is generated to tell you that the CMOS memory contents may have been corrupted and therefore some settings may be wrong. BIOS’s react in different ways when encountering this type of error. Some will warn the user and then continue on with whatever settings were in the CMOS. Others will assume that the settings that were in the CMOS were corrupted and will load default values stored in the BIOS chip by the manufacturer as a safety measure. Others will correct the settings and proceed through the boot process. The error message will indicate to you what your system is doing.

Diagnosis: The most common cause of checksum errors in CMOS is a battery that is losing power. Viruses can also affect CMOS settings, and motherboard problems can also affect the stored values.

Recommendation: You should make sure that all of the BIOS settings in the system are correct, by rebooting the system, going into BIOS setup and double-checking all the values.

• Replace the CMOS battery on the motherboard.
• Scan your system for viruses.
• Look for other signs of motherboard problems.
• Check your computers power supply to insure that it is being properly cooled and it is providing the correct voltages.

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