CMOS Checksum Error

Question

I'm helping troubleshoot a CMOS checksum error they are getting on their Inspiron 546 desktop. The date and time are lost every time the computer is turned off, so we started with replacing the battery. The date and time are still lost every time the computer is turned off with the new battery. Thinking the new battery may also have been dead, the voltage of both batteries was checked, and is reading 2.8 to 2.9 volts. Other than getting the error message, entering the CMOS setup and then exiting without saving changes, and having to set the date and time every time the computer is started up, everything else with the computer seems to be fine and functioning normally. Something I've noticed is that every time the computer is restarted, the date and time are not reset to the same default date and time. For example, one time it was 31 Dec 2001 11:00 PM, and the next time it was 3 Jan 2002 10:00 PM. I'm wondering if this could be a clue as to what may be causing the issue? I would have expected it to reset each time to the same default date and time if it is not detecting battery power, but perhaps I'm misunderstanding. I know from reading the manual that the CMOS checksum error can also indicate a problem with the motherboard, but there is nothing obviously wrong that I can visually detect. Any ideas as to what else I can try to troubleshoot this problem are greatly appreciated. Thanks in advance.

DELL-Rishi · Answer

Hi GDStone,

Firstly, I would want to confirm if there are any other hardware issues that might be conflicting. So, restart the system and keep tapping on f12 key to enter diagnostics/pre-boot system assessment - let it complete the test - make a note of any errors that you may encounter. Also run the extended memory test.

The 2 dates you have mentioned, is that in BIOS or in windows? Is the date and time correct within OS? To reset the CMOS battery settings, first - remove the CMOS battery and turn on the system. It will generate an error. Then turn off the system and put the CMOS battery in and turn it back on. If you have set an admin password within BIOS, please remove the password and then save and exit.

Try updating the BIOS from support.dell.com - http://dell.to/1kGWIcI - you need to enter the service tag and click on drivers and downloads - download and run the BIOS update.

Keep us updated.

GDStone · Answer

Thank you very much for your suggestions, Rishi. I will try them out and then report back, although it will be a couple days before I next see the person who has the problem computer.

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