Archived from groups: alt.comp.periphs.mainboard.asus (
More info?)
In article <c538q9$2nflfh$1@ID-54604.news.uni-berlin.de>, "Linea Recta"
<mccm.vos@abc.net> wrote:
> "Paul" <nospam@needed.com> schreef in bericht
> news:nospam-0704041540090001@192.168.1.177...
> > In article <c514ln$2nr8b0$1@ID-54604.news.uni-berlin.de>, "Linea Recta"
> > <mccm.vos@abc.net> wrote:
> >
> > > "Paul" <nospam@needed.com> schreef in bericht
> > > news:nospam-0604041523470001@192.168.1.177...
> > > > In article <c4v27q$2nhoic$1@ID-54604.news.uni-berlin.de>, "Linea
> Recta"
> > > > <mccm.vos@abc.net> wrote:
> > > >
> > > > > "Rob Hemmings" <SpamDaMan@nowhere.noway.con> schreef in bericht
> > > > > news:c4ul2d$937$1@south.jnrs.ja.net...
> > > > > > "Linea Recta" <mccm.vos@abc.net> wrote in message
> > > > > > news:c4uas3$2nn6n0$1@ID-54604.news.uni-berlin.de...
> > > > > > > Sometimes when I switch the computer on, it boots directly into
> the
> > > BIOS
> > > > > > > setup. (luckily nothing gets changed, because I use passwords).
> > > > > > > Since I don't want to enter the setup, I press the reset button,
> and
> > > > > then
> > > > > > I
> > > > > > > can boot the OS normally.
> > > > > > > What can be wrong?
> > > > > > > I use NAV (updated each day).
> > > > > >
> > > > > > If the 3v lithium mobo battery is running down, the board may be
> > > > > > detecting a CMOS (BIOS settings stored here) checksum error
> > > > > > and taking you straight into the BIOS. If you can measure the
> > > > > > battery voltage, make sure it's above 3v. If you can't, try a new
> > > > > > battery.
> > > > >
> > > > > All right, I'll check it out. (I wonder when they're going to invent
> a
> > > > > battery which gets recharged by the system power supply...)
> > > >
> > > > A coin cell would blow up if you charged it. A rechargable battery
> > > > would self discharge and not give you the same continuous service
> > > > life that the coin cell does. It is really a good design, except
> > > > when the battery is dead to begin with. The only thing that would
> > > > be better, is using a larger cell, and that would be more
> > > > expensive to replace.
> > > >
> > > > You might want to check your fan speed. On my computer, I have a
> > > > PS fan connected to a fan header, and on cold boot, the PS fan
> > > > runs so slow, the RPMs are less than the threshold in the power
> > > > monitor. The BIOS prompts me to fix it, but by the time I enter
> > > > the BIOS, the PS has warmed up enough that the fan speed is
> > > > then above the threshold, and there is nothing to fix. So,
> > > > check out your fan speed as a root cause. It could be the
> > > > BIOS has an option to [Ignore] the fan in question.
> > >
> > >
> > > I suppose the battery is only to keep time/date clock running? Are the
> other
> > > settings kept in flash memory?
> >
> > The Southbridge has two areas of silicon in it. One is tiny and
> > contains 256 locations of SRAM (called the CMOS ram) plus a real
> > time clock. There is a 32KHz crystal outside the Southbridge that
> > oscillates just like in a wrist watch, and it feeds the RTC.
> > So, time and settings are contained in that part of the Southbridge.
> > (That part of the chip is sometimes referred to as the "CMOS well",
> > due to the isolation techniques used to separate that part of
> > the chip from the rest of it.)
> >
> > From the ICH5 datasheet:
> >
> > "Real-Time Clock
> > < 256-byte battery-backed CMOS RAM
> > < Integrated oscillator components
> > < Lower Power DC/DC Converter implementation"
> >
> > The Southbridge has two power supplies. The majority of the Southbridge
> > runs from the main power outputs of the PS. The tiny chunk of
> > silicon containing the CMOS ram and RTC is powered by the standby
> > supply, and it consists of a diode-ORed combination of +5VSB (reduced
> > to 3V) and the 3V coin cell. When the computer power cord is unplugged,
> > the coin cell is the sole source of power for the Southbridge
> > standby. The dual diode prevents the 3V coin cell from being
> > charged by the +5VSB derived source.
> >
> > When the computer is plugged in and switch on (on the back) but you
> > haven't pushed the button on the front, the +5VSB is operating and
> > the green LED on the motherboard will be lit. At this time, the
> > dual diode cuts off the coin cell, so no juice is drawn from the
> > coin cell. So, really, the only time the coin cell is draining is
> > when the switch on the back of the computer is in the OFF position
> > or the cord is pulled.
> >
>
>
> Thanks for this usefull information. Does it apply specifically to my MB, or
> generally?
> I'm customed after work, to close down Windows and finally switching off all
> power(consuming) blocks, i.e. the computer itself and all periferal devices.
> But if leaving the computer connected, as I understand, adds to the life of
> the coin cell?
I think they are all like that. If you unplug the computer and
leave it in a corner for 2 or 3 years, that might be enough to
drain the coin cell. Leaving the computer plugged in and
the switch on the back in the ON position, removes the load
from the coin cell, and then the coin cell will last for
its shelf life (whatever that is). When in the ON position but
not running Windows, the computer is wasting up to 10W of power
(to make +5VSB and run stuff like DRAM refresh for the sleep
function), so you'll have to compare the cost of the electricity
with the cost of replacing the coin cell in a few years.
HTH,
Paul
Facebook
Twitter
Instagram