CMOS Checksum Error fix guide

CMOS Checksum Error

Error "CMOS checksum error - Default loaded" and its relatives "CMOS checksum bad", CMOS checksum failure (the exact text of the error depends on the motherboard manufacturer) literally translates to "CMOS error of checksum, default parameters loaded". This means that the current power on the computer, the indicator of the amount of data stored in the CMOS memory, does not match what was recorded when the computer was last started. The comparison of these data is necessary for the correct start of the operating system, but their discrepancy does not always indicate an irreparable problem.

Reasons for this message:

1- Weak BIOS battery

2- Some viruses affect the BIOS

3- Problems with the motherboard

Some solutions may help:

1- Scan your device with one of the Anti Virus Programs

2- Check the CMOS battery

3- Check the Power Supply because it may affect the functions of the motherboard components

And the quick solution:

Enter "CMOS Setup" by pressing the "Delete" key during the device startup. And

Choose "Set CMOS to Default Setting" then save and restart

Option 1: Reset the CMOS memory

The first step is to try simply resetting the CMOS memory manually and then turn the computer on and off 2-3 times to see if the error reappears. This is done through a battery or other elements on the motherboard. The procedure itself is very simple and even an inexperienced computer user can easily implement it. In the article in the link below, see Ways 2-4 explain how to do this and use the method that works best.

You can also do a regular BIOS reset - chances are even that will help. The algorithm is shown in the same article mentioned in Method 5... The instructions are suitable for all types of BIOS, despite the differences in appearance.

Option 2: Replace the battery

A coin cell battery (CR2032) is always present on motherboards to store data in CMOS memory. Years later (usually 5-8 years) it exhausts its resource, which is why the information in CMOS is not stored for a long time, being constantly thrown away. The consequence of this is not only various failures (for example, resetting the system time), but also displaying the error under consideration today. Anyone can replace the battery, as this operation is no different from the same procedure for another device. However, we suggest you familiarize yourself with it in more detail using the guide at the following link.

Laptop owners will have a more difficult time - for this it is necessary to remove the bottom cover, which is not always possible to do smoothly due to the design features of a certain model. Therefore, if you are not confident in your abilities, it is better to contact computer specialists - such a procedure should not be expensive.

Option 3: Update the BIOS version

Updating the BIOS version can fix some problems and software problems. This process is simple, but you need to treat it with care, because thoughtless actions can lead to the fact that the computer will not turn on at all.

Other troubleshooting tips

Self failure can occur even if the power is turned off incorrectly. Do not turn off the computer by holding down the "Power" button or by other drastic means. Use a classic shutdown, where the computer will shut down normally.

Some people can't press any keys during the "CMOS Checksum Error - Defaults Loaded" message screen... In this case, connect the keyboard directly to the motherboard if it's connected to the front of the system board block. Sometimes it is effective to disconnect the front panel itself from the motherboard (its USB interface is connected by a wire), in case of a breakdown, where there is a problem with the operation of the USB ports. And when you use a wireless model, you will need to connect a wired one for a while.

This usually also happens after resetting the BIOS settings to defaults, with which the USB interface support has been dropped, which is more typical of older computers and BIOS versions. If you suddenly have a PS / 2 keyboard and the corresponding port on your motherboard, using them can help you. Go to the BIOS and find USB support in one of the sections, enabling it (by setting the option to "Enabled").

When the implementation of all recommendations does not lead to a positive result, you should check the motherboard for the presence of damaged capacitors. Likely swollen, dry or oozing, they cause the entire computer to malfunction. In the absence of knowledge about replacing capacitors, there is nothing else to do but contact a service center or buy a new motherboard.

The error may indicate more serious problems with the motherboard, which can only be detected by a person who understands the principle of operation of such equipment.

Reinstalling RAM strips in other slots (ie you have to swap them) or disabling one of them rarely helps. If the second method helped, most likely the disconnected tape is damaged. For a replacement, look for the exact same model or similar features.