# CMOS Checksum bad - bios flash?



## kaan921 (Oct 27, 2012)

After I flashed BIOS with WinDPtool that was in the BIOS folder, I restarted the computer, then I got this error: CMOS Checksum bad - Press f1 to run setup.

I bought new CMOS Batteries to my computer and replaced it with the old one, but it doesnt seem to work. The BIOS wont save when I choose "No errors" on Halt on in BIOS CMOS Features... so, my question is kinda gently; how do i fix it? 

i set the correct time and date, and that is saving.. not the other options in bios 

i got an acer veriton m670g computer and installed the p03 bios, and the p04 is the latest.. i cant boot from cd due to bios is doesn't let me first boot thingie
opcorn:


----------



## Wrench97 (May 10, 2008)

When you press F1 to enter the bios are there any options other then the date and time setting?


I moved you over to the Motherboard section since this has nothing to do with Windows but rather the bios flash.


----------



## kaan921 (Oct 27, 2012)

Yes, all options is available.. But only date and time is changeable


Thanks for fat response!


----------



## Wrench97 (May 10, 2008)

For your model I'm seeing a bios version of R01.A4 is that what you used?
Acer Support: Downloads & Support Documents - Desktop / Veriton / Veriton M670G


----------



## kaan921 (Oct 27, 2012)

No, i installed the bios that is ending with 3.. Also the second last..


----------



## Wrench97 (May 10, 2008)

Ok so it was the P01.A3 that's fine.

I don't suppose there is a floppy drive in that is there?


----------



## Wrench97 (May 10, 2008)

Another thought have you tried to load the default settings, it should tell you onscreen which F key to press to load defaults.


----------



## kaan921 (Oct 27, 2012)

Also, I can't boot from usb stick or cd..  

and, I have tried to load to all default settings, but that doesnt seem to work at all.. it doesnt save.. i have tried like 6-7 lithium batteries and after replacing the lithium battery, it asks me to set the current time and date, I do it and save'n exit..
then the normal error is coming 

I know the problem; i need to change the "halt on" to "no errors" from "Yes, all but keyboard" in Standard CMOS Features tab in bios..
but it doesnt save
:banghead:


----------



## Wrench97 (May 10, 2008)

Halt on all errors not the answer, what's happened is a bad flash, the file was corrupt, not read completely or a Windows issue interrupted the flash process.
Since it's booting and allowing access to the bios reflashing using the dos method and a floppy drive may be the solution. If not then either a bios chip replacement(if it is the socketed type) or a professional repair by flashing though the serial port for the soldered on type of bios chip).


----------



## kaan921 (Oct 27, 2012)

i got a floppy drive, but i dont got a floppy disk  dunno how i can get it tho

but, so what should I do? If I call Acer, they want 5$ each minute I talk with them ++ they will have money for doing this process..

where can i buy bios chip?


----------



## Wrench97 (May 10, 2008)

I'm not sure which type of chip you have, the one type just plugs into a socket the other is soldered on to the motherboard.
There is a site called the biosman that sells preprogramed chips, they would probably know what Acer is using on that model> 828155


----------



## kaan921 (Oct 27, 2012)

how can i check what kind of i got?  i have the chassis opened now..


----------



## Wrench97 (May 10, 2008)

It's either a square or a rectangular chip usually near the battery, it may actually say bios or Award on it. There are a lot of different Q45 chipset boards, since Acer does not manufacture it's own components(like most OEM's) and there are not any support manuals listed on the site I have no way of knowing what board they used it that model.


----------



## kaan921 (Oct 27, 2012)

Isn't it really something different ways to fix this on? 

I have read that CMOS Checksum bad means only that the BIOS only got wrong settings and I need to correct them, but due to I can't save my settings in BIOS


----------



## Wrench97 (May 10, 2008)

None that I know of.


----------



## kaan921 (Oct 27, 2012)

I found the bios chip in my computer and it says "686 AMIBIOS WM88 2079"

if i change bios chip? are u sure it will work 100%?  i have used over 20 usd for the cmos batteries..


----------



## Wrench97 (May 10, 2008)

Is the chip in a socket or soldered on?


----------



## kaan921 (Oct 27, 2012)

http://2a.zol-img.com.cn/product/68_500x2000/436/ceSVEXYPEGThY.jpg
its like in this type, but the black thing is in a different size of course..


----------



## kaan921 (Oct 27, 2012)

http://2a.zol-img.com.cn/product/68_500x2000/436/ceSVEXYPEGThY.jpg
its like in this type, but the black thing is in a different size of course..


----------



## Wrench97 (May 10, 2008)

That's soldered on, not in a socket.

This is the socket type


----------



## kaan921 (Oct 27, 2012)

oh , then its not in socket.. could u say me which chip i need to buy? i am living in norway, and it would be nice if the website ships to norway..


----------



## Wrench97 (May 10, 2008)

You will not be able to solder it on your self, that takes special equipment and ability(experience). best bet is to replace with a refurbished board or find a local shop that can send it out and have it flashed through the serial port.


----------



## andiles (Nov 13, 2012)

Wrench97 said:


> Halt on all errors not the answer, what's happened is a bad flash, the file was corrupt, not read completely or a Windows issue interrupted the flash process.
> Since it's booting and allowing access to the bios reflashing using the dos method and a floppy drive may be the solution. If not then either a bios chip replacement(if it is the socketed type) or a professional repair by flashing though the serial port for the soldered on type of bios chip).


Do you have a step by step guide on out to update from the Floppy drive if I do have a floppy disk?


----------



## Wrench97 (May 10, 2008)

Nothing more then is in the read me file or the manual for the board.


----------



## andiles (Nov 13, 2012)

Thanks, All working.


----------

