Prev: How hot is too hot?
Next: P4C800-E Deluxe Dead?
From: Esteve Valentí on 30 Jul 2010 04:29
hello... my computer loss the bios information... i has changed the
battery and
then reconfigured the bios data, time, etc... but when i unplug the
computer of the
electric cable loss the bios configuration... and i do not know way
this do and how
to solve...
The bios it's the latest beta version of the support web of my
motherboard ASUSP5GD2-X
Maybe can be because it's a beta version?

Now I has unplugged the frontal case usb because one runs right and the
other
do not detect the things plugged... but the light appears... and I
thing this can be
thing that consume the battery energy... I don't know...

Thank's !!!


From: Paul on 30 Jul 2010 06:07
Esteve Valent� wrote:
> hello... my computer loss the bios information... i has changed the
> battery and
> then reconfigured the bios data, time, etc... but when i unplug the
> computer of the
> electric cable loss the bios configuration... and i do not know way this
> do and how
> to solve...
> The bios it's the latest beta version of the support web of my
> motherboard ASUSP5GD2-X
> Maybe can be because it's a beta version?
>
> Now I has unplugged the frontal case usb because one runs right and the
> other
> do not detect the things plugged... but the light appears... and I thing
> this can be
> thing that consume the battery energy... I don't know...
>
> Thank's !!!
>

The CMOS battery is not connected to the USB ports. The USB port, and any
LED on a peripheral device, run from +5V or +5VSB.

Your motherboard has a hardware problem. The power from the battery
is not reaching the Southbridge (which holds the 256 byte CMOS RAM
and RTC clock).

Have you ever used the jumper to "clear the CMOS" ? It could be,
that you used that jumper, while the computer still had power inside
the chassis. And that damaged a diode in the battery circuit.

This picture, is your motherboard, with the "AI Proactive" heatsink
removed from the Southbridge chip. You can see some components near
the CMOS jumper. I'd be visually examining the components there, for
damage. In the past, Asus motherboards used a dual diode, with common
cathode, in the battery circuit. It has "K45" printed on it, but
you'd need a magnifying glass to read it. I can't see it in the picture,
but if it is in the circuit, it would be in the bottom right of this
photo. The thing has three legs, a black body, and "K45" printed
on it, and it could be burned or damaged.

http://www.ibora.net/html/contants/p5gd2_x/asus_p5gd2_x_4.jpg

To see the part of the circuit that is damaged, see PDF page 76 here.
The two Schottky diodes, are inside the same three legged package.
The lower diode is "open circuit". To trace it, you could start from
the battery, using a multimeter, to find the 1Kohm surface mount
resistor, then trace from the other side of the resistor, to some
three legged part which is broken. This is not easy to do, and takes
time. You would replace the dual diode, with a new one.

http://www.intel.com/Assets/PDF/datasheet/301473.pdf

And this is what a replacement diode would look like. I have three
Asus motherboards using this particular part for the task. It is always
possible they could use a different one than this, but this one is
popular.

( BAS40W-05, on page 2 it says "K45 = BAS40W-05" )

http://www.diodes.com/datasheets/ds30114.pdf

Paul
 | 
Pages: 1
Prev: How hot is too hot?
Next: P4C800-E Deluxe Dead?