When i switch the ups power on my pc automatically starts and the the BIOS setup page comes and in it,it is written CMOS checksum error and asks me to set the time.even after setting everything when i completely shut down the pc along with the ups and start it again it shows the same thing.i even checked for virus using licensed and up to date kaspersky anti virus 2010.please give a proper solution ?

When a Power Supply is plugged into power, there is a constant 5 Volts present. The 5 Volt Standby Power.

You press the Power On button.
This in turn presses against the Power On switch, located inside it's plastic assembly.

The Power On switch is a Momentary Contact Switch.
Temporary closing it activates the Soft Power On circuit.
A 5 Volt circuit that utilizes the 5 Volt Standby Power.

The Soft Power On circuit 'excites' the Power Supply, and turns it on.
(Sounds like a seedy novel)

The first chipset (Integrated Circuit) to receive power is the BIOS chipset.
The Basic Input/Output System program is initialized.

BIOS looks to see what devices are connected, does a Ram Memory count, turns the Processor on, and hands the computer over to the Operating System.

A checksum is computed as an error-detecting code, to protect the BIOS settings stored in CMOS.
Each time the computer is turned on, this number is re-computed; and checked against stored values.

If they do not match an error message is generated, to tell you the CMOS memory contents may have been corrupted; and therefore some settings may be wrong.
Your BIOS assumed the settings were incorrect, and loaded BIOS default settings; stored in BIOS.

(Default = factory settings)

CMOS Checksum Error Defaults - Loaded

New battery? Nope didn't help.
Clear CMOS, and password reset? Nope didn't help.

Leaves Virus as the problem, or hardware component/s on motherboard; are bad.

My thoughts?
Bad motherboard.

("BAD motherboard. NO,...........you know you have been bad,....don't give me that look. You're a bad motherboard."

Lol!)

That's my diagnosis.


(Unless you put the CMOS battery in upside down.
+ goes UP)

Regards,
joecoolvette

Error BIOS ROM CHECKSUM - SYSTEM HALTED.
Cause Bad Hardware
Solution Unfortunately this indicates that your computer BIOS ROM chip or Motherboard is physically bad. It is recommended that you contact your computer manufacturer or take the computer into local service center for repair.
If you wish to repair this issue yourself the motherbard will need to be replaced.
This error is not the same as a CMOS Checksum Error, which refers to corrupted values of the CMOS settings, the ones you set through the BIOS setup program. This error means the contents of the BIOS code itself are damaged.

The BIOS ROM chip on the motherboard is probably faulty. It could also be another component on the motherboard.

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 hopefully against a recent

If you have reset the CMOS memory you need to go into the BIOS setup screen and reconfigure the BIOS. To do that you need to press a key while the computer is booting. Usually F2 but can be other keys. It should tell you on the bottom of the first screen which key to press to enter BIOS setup.
If you don't know the settings the should be one for optimal defaults - use that one. You will also need to reset the time and date.
Save, Exit and re-boot and everything should then work.

This error is not the same as a CMOS Checksum Error, which refers to corrupted values of the CMOS settings, the ones you set through the BIOS setup program. This error means the contents of the BIOS code itself are damaged.


During the boot process you will see on the screen a certain key to press to enter setup
Press and hold that key during the boot up process to enter BIOS you can load failsafe defaults or load optimized defaults ,press escape then press f10 to save to cmos to restart
You will also need to set the time and date

In the main or system setup screen you should be able to see the date and time Using your arrow keys navigate to the date and change the date. Once highlighted on the month, day, or year, press your arrow keys or your page up / page down keys to change the date.
hope this helps you

This error is not the same as a CMOS Checksum Error, which refers to corrupted values of the CMOS settings, the ones you set through the BIOS setup program. This error means the contents of the BIOS code itself are damaged.

The BIOS ROM chip on the motherboard is probably faulty. It could also be another component on the motherboard.

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 (hopefully against a recent

If you have reset the CMOS memory you need to go into the BIOS setup screen and reconfigure the BIOS. To do that you need to press a key while the computer is booting. Usually F2 but can be other keys. It should tell you on the bottom of the first screen which key to press to enter BIOS setup.
If you don't know the settings the should be one for optimal defaults - use that one. You will also need to reset the time and date.
Save, Exit and re-boot and everything should then work.

This error is not the same as a CMOS Checksum Error, which refers to corrupted values of the CMOS settings, the ones you set through the BIOS setup program. This error means the contents of the BIOS code itself are damaged.


During the boot process you will see on the screen a certain key to press to enter setup
Press and hold that key during the boot up process to enter BIOS you can load failsafe defaults or load optimized defaults ,press escape then press f10 to save to cmos to restart
You will also need to set the time and date

In the main or system setup screen you should be able to see the date and time Using your arrow keys navigate to the date and change the date. Once highlighted on the month, day, or year, press your arrow keys or your page up / page down keys to change the date.
hope this helps you

Hi There.

Symptoms
* cmos checksum error messages
* error with date time error

Solution
* Replace CMOS battery.

Procedure

1. Locate your CMOS battery.




2. Turn of your Desktop.
3. Remove the power cable from your Desktop.
4. Press power button to discharge your Desktop from electricity.
5. Desktop should be laid down horizontally.




6. Remove the battery and avoid forcing.
7. Replace the battery with same model or equivalent.
8. Put the new battery firmly in the allocated slot. (Positive side should be visible).
9. Plug the power cabe and start up your PC.
10.Enter Bios by pressing DELETE or F2 and load defaults save and quit, it will reboot automatically.
11.Enter Bios modify settings save and quit.
12.The End

Hopefully this information helps.
Thank you for using FixYa.

Hi there,

When starting your PC, the following error message is displayed:

CMOS wrong
CMOS MEMORY size WRONG
CMOS Checksum Bad
CMOS checksum error defaults loaded
Warning! CPU has been changed please re-enter cpu settings in the cmos setup and remember to save before quit!
You are prompted to:

Press F1 to resume
Press F2 to load default values and continue


This is due to the fact that the CMOS, which contain data related to the BIOS, has been reinitialized and that your PC has been reset to factory settings.

Solutions:

Reinitializing the BIOS

• • Before making any costly maintenance try to reinitialized the BIOS.
• Change BIOS battery
  • If the problem persist this may be due to the fact that the battery powering the CMOS (when the computer is shut down allows the CMOS to store information), is depleted.
  • The CMOS battery is a small pin found on the mother board, you can refer to the manual provided with your motherboard to change it or have the nearby computer technician change it for you if you don't want to risk any damage.
  • More information with: Replacing the battery of your motherboard (CMOS battery)

Post back if it is not working we will be happy to help you.
Hope this helps.
Cheers!!!!

CMOS checksum errors
Explanation: A checksum is computed as an error-detecting code, to protect the BIOS settings stored in the CMOS memory. Each time the system is booted 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. BIOSes react in different ways to encountering this sort 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 "for safety reasons". The error message will indicate which 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: Follow the instructions in this section to address the CMOS corruption. 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 (hopefully against a recent BIOS settings backup).

Sounds like you CMOS battery is FLAT, please locate and replace, it is a 3.6V flat "Cell" This may just sort you out. Checksum error is because, something is different from the stored checksum it has in memory.

You can try flashing/updating the BIOS if nothing works.

Hi Oliver, the most common error related to the message,
(Bios Rom Checksum Error). Someone has left a floppy disk in the floppy drive. Once the floppy disk has been removed press the reset button on the PC, your windows will start normally. Next place to look is in your bios.
Open your manual to page 27.
Enter your bios & go to the title Advanced BIOS Features. Check First, Second & Third boot devices they should be as follows. Floppy disk drive, CD-ROM drive & primary hard disk drive. If both of the above are ok than try clearing the cmos/bios by resetting the cmos jumper (JP1) location on page 5. Descriptions of page five on page 6. CMOS settings on page 9.
When your system restarts re-enter your cmos & reset up your bios settings. Lastly if none of the above has fixed the error message, than remove the cmos battery & check its voltage. It should maintain 3volts. If yours' is lower than 3volts replace the cmos battery. There is one other possible fix. It’s an option not given lightly. Flashing a cmos/bios is not recommended unless all other options have failed.
Bios link for the EliteGroup P4VMM2 V8.1
http://www.ecs.com.tw/ECSWebSite/Downloads/ProductsDetail_Download.aspx?detailid=436&DetailName=Bios&DetailDesc=P4VMM2%20%20(V8.1)&CategoryID=1&MenuID=82&LanID=0
Main web site;
http://www.ecs.com.tw/ECSWebSite/Products/ProductsDetail.aspx?CategoryID=1&DetailID=436&DetailName=Feature&MenuID=52&LanID=0

Good luck Oliver!
Mike

Replace the CMOS battery that is busted. after replacing configure in bios setup and load bios setup default.