CMOS checksum error

Category: Hardware

When I boot up, I get a CMOS checksum error message and I must press F1 to continue or DELETE to enter Setup. How can I solve this problem?

Most likely the battery on your system board is kaput. They are cheap, easy to find at most electronics retailers, and pretty simple to replace.

After opening the case of your system unit, look for something about the size and shape of a quarter mounted on the system board. Usually the battery sits under a tight clip and you can remove it by lifting the clip. Sometimes they snap into a socket and you have to push a little tab to release them.

After replacing the battery, start up your computer and press the appropriate key to enter the BIOS setup screen. (Usually it's the DELETE or INSERT key. Watch the screen for instructions or consult your manual.)

Set the system clock to the correct time, then save and exit. If your computer works normally now, you're all done. If it doesn't recognize one or more hard drives, go back into Setup and look for the hard drive "Auto config" or similar. Sorry if that's a little vague, but every BIOS is different, so it's impossible to give more detailed instructions. Poke around a bit, you'll find it!

 
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This article was posted by on 28 Jun 2005


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Most recent comments on "CMOS checksum error"

(See all 25 comments for this article.)

Posted by:

henry
27 Mar 2008

Hi, could u please help me solve this problem? When i started up my comp it leads me to the bootup screen, where u get bootup in safe mode, normal mode ect. the only change to this creen is that the words are fuzzy and appears in combination of upper and lower case and some unsually simbols. When i selected one of the option to bootup the computer froze.

I have however, tried to enter the blue setup screen, i could get in there but the screen appears to have vertical lines all over.

I also have tried reformatting the computer but it was no use because it froze at starting up widows screen.

I have read all the help from above i'm not sure if mine is related 2 the battery or some kind of viruses attacking my bios, if that's possible. Much appreciated if u could help me out.

EDITOR'S NOTE: My first guess would be your monitor or video card is going bad. I've never seen a BIOS virus, and I'm not even sure they exist. But it's possible your BIOS chip was damaged, perhaps by heat. If so, you'll need a new motherboard.


Posted by:

Rit
17 Apr 2008

Hello, I am having similar problem as the obove people. When i start up my pc, i get the cmos checksun error and cannot press delete or F1, since the keyboard does not seem to be working, even thought the num and scroll lock lights are showing up. Did lots of research on this matter, but to no avail. I even considered changing the cmos battery, but that did nothing. Hoping someone can help me. Thanks.

EDITOR'S NOTE: Did you try plugging in another keyboard?


Posted by:

Rit
17 Apr 2008

I am trying find an alternative, atm i am waiting for a ps/2 to usb converter to see if that changes anything, as for using a completely different keyboard, will have wait till i get a new one. Will inform about how things are going on later, as this has so far been such a big dead end in my atempt to replace a broken motherboard with a new one. Thanks for responding promptly, really appreciated.


Posted by:

Rit
19 Apr 2008

Seriously guys, using a different keyboard, solved my problem.. was so releaved when it did work. If u happen to get same problems as me, just get a really cheap ps/2 keyboard and it should do the trick.. My problem was infact that my previous motherboard fried everything along with it... "thanks" Emachines.

Anyway,Bob, ur a true hero.

And conserning the cmos battery, i bought new ones in vain, its not a big deal to get that error, and funnily enough in my case i was one of the few how got this problem where my battery was fine but keyboard kind screwed me :(. so HAPPY it worked.. YAY


Posted by:

carl
23 May 2008

I used gigabyte P35 chipset motherboard with E6750 CPU and windows vista 64 + Patriot 4 gigs DDr II and a ASUS 8800 gts video card. Now I upgraded my Motherboard to same brand p35 chipset but higher level than previous MB...Now everything is installed and fire it up ..I get "file leader checksum does not match the computed checksum ...Please what should i do?..

EDITOR'S NOTE: I think that's a RAM error. Try swapping out one (or more) RAM sticks and see if the problem persists.


Posted by:

oppie
08 Aug 2008

i am facing the cmos check sum error default loaded. when i pressed f1 or del key it dosn't work. anyone can help me..... please........send me mail as soon as possible....yes i put a newbattery in and still have the same thang how can i get my keyboard work on this computer. or get my computer reboot where i can use it?


Posted by:

Deepak
17 Nov 2008

Hi , I am facing problem whenever i startup my pc the error displays as "CMOS Chksum error " . I have changed CMOS battery also still this error displays ,plz help me.


Posted by:

Tirthankar
03 Feb 2009

hi, i replaced my cmos battery and i still have to set time and date on every time... after 4 to 5 hours this happens .... any solution??


Posted by:

boy
12 May 2009

am facing the cmos check sum error default loaded. when i pressed f1 or del key it dosn't work. anyone can help me..... please........send me mail as soon as possible....yes i put a newbattery in and still have the same thing how can i get my keyboard work on this computer. or get my computer reboot where i can use it?


Posted by:

SUMANTA SARKAR
22 May 2010

Hi , I am facing problem whenever i startup my pc the error displays as "CMOS Chksum error " . I have changed CMOS battery also still this error displays ,plz help me.


Posted by:

Racecar56
24 May 2010

@ everybody with a "i replaced the battery but it still fusses" problem

Your motherboard's CMOS reset jumper might be on the reset position. Fix that ASAP. Check the motherboard's manual (if any).

If you don't know what any of this means, then it shouldn't be the problem.


Posted by:

julia
17 Jul 2010

Thank you so much for the post! Fixed my problem with "cmos checksum error"!!! When I read "setting system clock" after changing the battery, I was like, right, like that's gonna do anything. And it did!!! I set the system clock and saved settings, and it worked!


Posted by:

William Wong
12 Sep 2010

Help! I sometimes get CMOS Checksum Error. Defaults Loaded. I've just recently changed the battery and the same thing keeps appearing! Yet, sometimes there is no error when booting up! Please help!


Posted by:

madhawa
02 Nov 2010

when the starup my moniter display CMOS CHECK SOM ERROW msg, and also my key board not working.help me.......


Posted by:

Bikash
04 Nov 2010

Hi, I am using Gigabyte GA-8I915-GV motherboard and I have been facing CMOS checksum error... i have changed my battery n also I have short CMOS jumper but still I facing the problem what should I do! -Thank u!


Posted by:

Amit
15 Nov 2010

I am facing problem whenever i startup my pc the error displays as "CMOS Checkksum error"


Posted by:

Mohd
25 Dec 2010

When I boot up, I get a "CMOS checksum error" message and I must press F1 to continue or DELETE to enter Setup. How can I solve this problem?"
i replaced my cmos battery and i still have to set time and date on every time


Posted by:

Mohd
25 Dec 2010

"When I boot up, I get a "CMOS checksum error" message and I must press F1 to continue or DELETE to enter Setup. How can I solve this problem?"
i replaced my cmos battery and i still have to set time and date on every time & when i press start key for system staring & system take more time to start.


Posted by:

jiffry
11 Apr 2011

Dear sir,
Hi, I am using foxconn G31 MXP mother board. when i start my computer CMOS checksum error-Default loaded Press F1 to continue. sir help me,what i have to correct setting to solve this problem and i am expecting your reply please
thanks
with best regards
jiffry


Posted by:

prakhar lohar
01 Oct 2011

Hi , I am facing problem whenever i startup my pc the error displays as "CMOS Chksum error " . I have changed CMOS battery also still this error displays ,plz help me.


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