Jump to content


Register a free account to unlock additional features at BleepingComputer.com
Welcome to BleepingComputer, a free community where people like yourself come together to discuss and learn how to use their computers. Using the site is easy and fun. As a guest, you can browse and view the various discussions in the forums, but can not create a new topic or reply to an existing one unless you are logged in. Other benefits of registering an account are subscribing to topics and forums, creating a blog, and having no ads shown anywhere on the site.

Click here to Register a free account now! or read our Welcome Guide to learn how to use this site.

Photo

CMOS Checksum Bad


  • Please log in to reply
27 replies to this topic

#16 MrBruce1959

MrBruce1959

    My cat Oreo


  • BC Advisor
  • 6,190 posts
  • OFFLINE
  •  
  • Gender:Male
  • Location:Norwich, Connecticut. in the USA
  • Local time:01:21 PM

Posted 20 March 2010 - 01:08 PM

Hi Bobo.

Let me try to explain in better detail.

All Motherboards have what is called a BIOS chip, it stands for Basic In/Out System.

The BIOS is a firmware that is burned into an IC chip, it has two layers, one being ROM which stands for Read Only Memory, this is a non-volatile memory area, which under normal conditions can not be changed.
Then you have an EPROM section of memory which is programable and changeable by both the operating system and the systems owner (which is you).

The ROM section can only be changed by using a special program that is designed to FLASH (over-write) this section of memory. There is another part of memory that is rarely touched even with this proceedeure, which makes the system recoverable in the event a bad flash happens.

The EPROM section is the one that allows you and your operating system to make changes to allow hardware to become active as the computer executes its Power On Self Test (POST).

Once the system takes inventory of its hardware, it searches for a boot.ini file, once one is found, it passes control over to that command, which eventually loads your operating system.

Sometimes a user setting in the programable section of the EPROM can have an incorrect setting, which prevents a piece of hardware from functioning correctly once windows tries to take control of it.

There are two options a motherboard manufacture embedded into the BIOS to correct this problem.

Option # 1 is a setting in the main BIOS menu called LOAD SYSTEM DEFAULTS this option resets the BIOS to its unaltered factory settings. This same option is sometimes worded differently in other BIOSes as USE SETUP DEFAULTS.

Option # 2 Is a motherboard manfacture installs a feature called CLR CMOS, this involves safely shorting out the EPROM to system GROUND (which is harmless) and clearing all user settings back to factory defaults. The EPROM section of the BIOS is just like RAM, it needs a constant voltage supply to store the memory settings, this is why you need what is called a CMOS battery, it keeps the memory alive once the system is powered off, it stores your computers TIME and user settings.

The purpose of shorting the CLR CMOS pins is because capacitors which are used through-out your motherboard act as batteries and store voltages, even after the battery is removed, shorting out the CLR CMOS jumper, harmlessly discharges those capacitors and thus completely clears any and all possible CMOS settings.

Once this proceedure is done, the jumper is again placed in its nautral position, the battery is properly placed back into its holder and the system is powered back on. You have to enter the BIOS setup utility to set the correct DATE and TIME, as those were reset back to factory defaults.

you also have to make sure the BIOS redetects your harddrives, there may be a special menu called DETECT HARD DRIVES, which you just allow the system to choose based on what info it detects from the hardrives onboard ROM chip.

Make sure you have PLUG AND PLAY OPERATING SYSTEM INSTALLED? selected as YES, this way Windows has 100% control over which IRQs are used for your hardware and which memory addresses are used for your hardware's I/O addresses.

Long story short, using the CLR CMOS feature is safe to use.

Flashing your BIOS chip with a DOS related Flashing utility can sometimes fail and rewrite the ROM with corrupted data. (But if it doesn't fail, this proceedure can actually correct a corrupted BIOS with a more stable image)

I strongly suggest if you need a BIOS upgrade, if you choose to do it yourself, you do a lot of reading on the subject and follow any instructions your motherboard manuals say to do to to complish this.

Also I would recomend only using their flash utility and their recomended firmware!

Hope this info helps you.

Edited by MrBruce1959, 20 March 2010 - 01:11 PM.

Welcome to Bleeping Computer! :welcome:
New Members: Please click here for the Bleeping Computer Forum Board Rules
 
My Career Involves 35 Years as an Electronics Repair Technician, to Which I am Currently Retired From.
However, I Am Currently A 'Disc Jockey' at a Local Low Powered FM Radio Station. ~~ Bruce Edwards ~~

 
As a Volunteer Staff Member of Bleeping Computer, the Help That I Proudly Provide Here To Our BC Forum Board Membership is Free of Charge. :wink:

BC AdBot (Login to Remove)

 


#17 B_o_b_o

B_o_b_o
  • Topic Starter

  • Members
  • 42 posts
  • OFFLINE
  •  
  • Local time:07:21 PM

Posted 20 March 2010 - 01:19 PM

still non the wiser after reading all that techno babble

I just want to know how to stop the error message appearing on initial start up

can I not just reset whatever needs resetting within the CMOS screen(s)?

#18 MrBruce1959

MrBruce1959

    My cat Oreo


  • BC Advisor
  • 6,190 posts
  • OFFLINE
  •  
  • Gender:Male
  • Location:Norwich, Connecticut. in the USA
  • Local time:01:21 PM

Posted 20 March 2010 - 01:33 PM

still non the wiser after reading all that techno babble

I just want to know how to stop the error message appearing on initial start up

can I not just reset whatever needs resetting within the CMOS screen(s)?


Yes.

Just enter the BIOS at boot up and try the proceedure I mentioned above.

Choose LOAD SYSTEM DEFAULTS or LOAD SETUP DEFAULTS and see how things go.
Welcome to Bleeping Computer! :welcome:
New Members: Please click here for the Bleeping Computer Forum Board Rules
 
My Career Involves 35 Years as an Electronics Repair Technician, to Which I am Currently Retired From.
However, I Am Currently A 'Disc Jockey' at a Local Low Powered FM Radio Station. ~~ Bruce Edwards ~~

 
As a Volunteer Staff Member of Bleeping Computer, the Help That I Proudly Provide Here To Our BC Forum Board Membership is Free of Charge. :wink:

#19 B_o_b_o

B_o_b_o
  • Topic Starter

  • Members
  • 42 posts
  • OFFLINE
  •  
  • Local time:07:21 PM

Posted 20 March 2010 - 01:38 PM

still non the wiser after reading all that techno babble

I just want to know how to stop the error message appearing on initial start up

can I not just reset whatever needs resetting within the CMOS screen(s)?


Yes.

Just enter the BIOS at boot up and try the proceedure I mentioned above.

Choose LOAD SYSTEM DEFAULTS or LOAD SETUP DEFAULTS and see how things go.


ok I'll give this a try

would there be any implications afterwards to the way my PC would work...? would I have to re-load drivers or re-install programs..etc?

#20 MrBruce1959

MrBruce1959

    My cat Oreo


  • BC Advisor
  • 6,190 posts
  • OFFLINE
  •  
  • Gender:Male
  • Location:Norwich, Connecticut. in the USA
  • Local time:01:21 PM

Posted 21 March 2010 - 09:25 PM

No you would not have to reload any drivers.
Welcome to Bleeping Computer! :welcome:
New Members: Please click here for the Bleeping Computer Forum Board Rules
 
My Career Involves 35 Years as an Electronics Repair Technician, to Which I am Currently Retired From.
However, I Am Currently A 'Disc Jockey' at a Local Low Powered FM Radio Station. ~~ Bruce Edwards ~~

 
As a Volunteer Staff Member of Bleeping Computer, the Help That I Proudly Provide Here To Our BC Forum Board Membership is Free of Charge. :wink:

#21 B_o_b_o

B_o_b_o
  • Topic Starter

  • Members
  • 42 posts
  • OFFLINE
  •  
  • Local time:07:21 PM

Posted 22 March 2010 - 02:16 PM

ok entered BIOS setup utility and there is no option to reset to default values

across top of screen I have Main;Advanced;PCIPnP;Security;Boot;Exit

I checked within each screen and could not see anything that would allow me to pursue option 1

Edited by B_o_b_o, 22 March 2010 - 02:16 PM.


#22 cryptodan

cryptodan

    Bleepin Madman


  • Members
  • 21,868 posts
  • OFFLINE
  •  
  • Gender:Male
  • Location:Catonsville, Md
  • Local time:06:21 PM

Posted 22 March 2010 - 02:20 PM

Look around the bottom for it. Also it could be on the exit screen.

#23 B_o_b_o

B_o_b_o
  • Topic Starter

  • Members
  • 42 posts
  • OFFLINE
  •  
  • Local time:07:21 PM

Posted 22 March 2010 - 02:24 PM

Look around the bottom for it. Also it could be on the exit screen.


aha I had to press F5 to load defaults...I then exited by pressing F10 save config changes & exit and it has booted up normally

the big test will be when I boot up from cold i.e. the first time

I'll report back to see how I get on

#24 B_o_b_o

B_o_b_o
  • Topic Starter

  • Members
  • 42 posts
  • OFFLINE
  •  
  • Local time:07:21 PM

Posted 26 March 2010 - 06:33 AM

sweet success :huh:

the reset must have done the trick - thank you

#25 rolexoner

rolexoner

  • Members
  • 4 posts
  • OFFLINE
  •  
  • Local time:01:21 PM

Posted 27 March 2010 - 03:26 PM

but would if affect my BIOS settings by taking the battery out?


Yes taking out the battery will affect your BIOS... It would reset your BIOS. Any personalized settings you had would be lost. Not that big a deal tho...

#26 MrBruce1959

MrBruce1959

    My cat Oreo


  • BC Advisor
  • 6,190 posts
  • OFFLINE
  •  
  • Gender:Male
  • Location:Norwich, Connecticut. in the USA
  • Local time:01:21 PM

Posted 27 March 2010 - 04:51 PM

You're welcome B_o_b_o! :huh:
Welcome to Bleeping Computer! :welcome:
New Members: Please click here for the Bleeping Computer Forum Board Rules
 
My Career Involves 35 Years as an Electronics Repair Technician, to Which I am Currently Retired From.
However, I Am Currently A 'Disc Jockey' at a Local Low Powered FM Radio Station. ~~ Bruce Edwards ~~

 
As a Volunteer Staff Member of Bleeping Computer, the Help That I Proudly Provide Here To Our BC Forum Board Membership is Free of Charge. :wink:

#27 louisjenveygoogle

louisjenveygoogle

  • Members
  • 10 posts
  • OFFLINE
  •  
  • Gender:Male
  • Location:Oxford
  • Local time:07:21 PM

Posted 28 March 2010 - 01:38 PM

My Packard Bell iPower is great but it does something very annoying every time I turn it on.

Basically, I turn it on and it begins to boot up and I see the PB splash screen. Then in the blink of eye I sometimes manage to catch a glimpse of a black & white DOS error message CMOS Checksum Bad then the machine mimics a re-start and once again displays the PB splash screen then proceeds to boot into Windows 7 just fine.

Bizarre..but annoying..very annoying.

Any ideas of how I can resolve this?



Replace the CMOS Battery: http://www.infopackets.com/graphics/cmos+battery.gif


Thanks - if I take the battery out then would it lose any info inbetween me putting a new one back in?



"You would lose the clock settings"

#28 B_o_b_o

B_o_b_o
  • Topic Starter

  • Members
  • 42 posts
  • OFFLINE
  •  
  • Local time:07:21 PM

Posted 28 March 2010 - 02:22 PM

See my last post, my issue has been resolved. You can close this thread now.




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users