Re: BIOS change killed my computer.

Conor <conor.turton@xxxxxxxxx> wrote:
> John Doe says...

>> A reset input resets the device. The device should be powered
>> at the time reset is used.

> THe CMOS clear jumper on a motherboard isn't a reset. It merely
> disconnects the CMOS backup battery...

If the system does provide power alongside the battery, apparently
the CMOS/BIOS jumper does more than that on my mainboards, since
all I have had to do is shut down Windows and use the CMOS/BIOS
jumper to reset the BIOS.

If I ever have to clear CMOS again, assuming it has to be done by
hand and is not done programmatically, next time I probably will
unplug the power supply before using the jumper, as long as there
is any question in my mind about the matter. However, I would not
remove the battery.

> The battery is there to preserve the settings when
> the power is unplugged hence a computer which is never turned
> off at the wall will have a battery that lasts pretty much
> indefinitely.

Batteries can last pretty much indefinitely when in use, depending
on current drain of the device.

What is the specified current usage of a CMOS/BIOS?

Some CMOS devices use probably less than the leakage current of a
CR2032 battery.

Maybe mainboard power is for backing up the battery. The mainboard
manufacture ABIT calls mainboard power "the +5V standby power".
Their mainboard manuals are online, just like most others.






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Relevant Pages

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