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the question is if the battery dies do you loose the bios . thanks

Well, you will lose the clock, date info for sure, some settings. BIOS info isn't usually so important so turning of the system to replace the battery IS recommended. If you're daring* (want to see the world burn) don't power it off when you remove the battery. Consult your MB manual, find it online if needed, to determine the correct replacement battery part number. If you're lucky, it needs a CR2032, that is a popular coin battery used in many MB's, and it is often available at your local drug store or radio shack.

* For the love of your MB, please ground yourself to the PC case, power supply, just not the MB itself when pulling the battery. If you have to leave the system on to swap the battery, note the orientation and don't put it in the replacement backwards!

thanks mastavr6. but will i need to flash the i bios . my problem is i get the bios rom checksum error at start up and i can not get into bios . thanks all

2cans wrote:

thanks mastavr6. but will i need to flash the i bios . my problem is i get the bios rom checksum error at start up and i can not get into bios . thanks all

No, you won't. You may lose some customized settings as MastaVR6 said, but you won't lose the BIOS itself.

THe "checksum error" means the data saved in the CMOS is invalid, no battery, no saved data = checksum error; this is a standard error notification. A checksum error is not equal to a corrupt BIOS.

MastaVR6 wrote:

THe "checksum error" means the data saved in the CMOS is invalid, no battery, no saved data = checksum error; this is a standard error notification. A checksum error is not equal to a corrupt BIOS.

Yeah, that's the ticket. Don't try to reflash your BIOS, waste of time. Just replace the battery, go into the BIOS setup, check all the settings to make sure they're reasonable or reset to factory defaults, then exit with save. That'll clear the checksum error.

I've ruined a few mobos in my life flashing the bios just for the sake of having the latest bios. Avoid flashing your bios unless you can meet these two conditions.

1. You need to flash it because you are having problems that a stated bios upgrade would fix.

2. Be financially able to replace the motherboard in case the bios flash fails.


Replacing the battery is no big deal. Your bios settings will all reset to default, but all you have to do is go back into the bios setup and set everything back how you want it.

To the OP: Reiterating what others have already said, no, you won't lose the BIOS. You will lose any customized BIOS settings and the time/date, but the BIOS itself is stored in non-volatile memory and will remain intact even if the battery dies.

moresmarterthanspock wrote:

I've ruined a few mobos in my life flashing the bios just for the sake of having the latest bios. Avoid flashing your bios unless you can meet these two conditions.

1. You need to flash it because you are having problems that a stated bios upgrade would fix.

Unfortunately, the descriptions of the BIOS updates posted by mobo vendors frequently don't give enough detail to determine this. But yeah, in principle I agree -- don't update the BIOS just for the sake of updating the BIOS.

moresmarterthanspock wrote:

2. Be financially able to replace the motherboard in case the bios flash fails.

Or buy motherboards with socketed (user replaceable) BIOS chips. This is one reason (of several) that I prefer Asus motherboards, and stopped buying MSI (MSI typically solders their BIOS chips to the motherboard, making it very difficult to do a DIY BIOS chip replacement).

Also:

It is a bad idea to flash your BIOS if you suspect that you've got bad RAM, or if the system is experiencing serious instabilities. A corrupted BIOS update due to flaky hardware will brick the motherboard.

If you have a UPS, use it. Losing power during a BIOS flash is pretty much guaranteed to brick the motherboard.

thanks for all the replies , but i replaced the battery and im having the same problem ,checksum error dunno . i have built my last six pc and never ran into this

Does this motherboard have a PS/2 keyboard port, and if so are you using a PS/2 keyboard or a USB one? Some BIOSes won't recognize USB keyboards if the CMOS settings get cleared; you need to hook up a PS/2 keyboard to get into the BIOS and re-enable USB keyboard support.

2cans wrote:

thanks for all the replies , but i replaced the battery and im having the same problem ,checksum error dunno . i have built my last six pc and never ran into this

As I suggested before... After replacing the battery, go into the BIOS setup, check the settings and save them. This includes what others are suggesting as to setup -- check USB keyboard support, set date & time, etc. The save step will insure the user data is stored with the correct checksum. If this doesn't fix it, then maybe you have a bigger problem.

Two more possibilities to help with the checksum error:

1. Choose 'default' or 'load failsafe settings' or something along those lines in your BIOS setup. The name can vary depending on the mobo but it's usually found in the 'exit' menu. After rebooting, if the checksum issue is solved, go back into BIOS and set the appropriate options.

2. Do a CMOS reset following instructions in your manual. When I do this, aside from manual instructions, I like to unplug all power from the mobo (ATX power plugs), hit the power button a few times, and let it sit with the 'reset' jumper for about 10-15 minutes. I've done this most often due to a failed overclock that doesn't auto-recover, but it works for other BIOS problems too, short of a corrupt BIOS.