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From: JBC on 9 Jun 2010 14:12
The other day I switched on my ASUS A7N8X Deluxe Rev 1.04 MB and got no
video signal (yellow LED on monitor) as well as no other activity or
indications. After removing all cards, dusting off CPU heatsink and MB,
reseating DIMM�s and Vid card & swapping Vid card I still had the same
indications. So I decided to remove the RTC/Setup battery and reset
BIOS to defaults. Upon boot I got video and was able to enter the setup
utility but as soon as I �saved any� changes I got the same indications
as mentioned above. So I reset again, and again got video and was able
to enter setup but was unable to �save any� BIOS settings without it
reverting back to the �black screen of death.� I repeated it several
more times to ensure that it was consistent, and it was.

So my question is: with the indications above, can anyone tell what the
probability is that the problem is the BIOS chip or that it�s the MB
circuitry that supports the BIOS chip. I really don�t want to spend the
money on the chip just to find out it�s the board.

TIA,

Joe
From: GMAN on 9 Jun 2010 14:41
In article <149ce$4c0fd9e9$4831ece8$26365(a)FUSE.NET>, JBC <spheresofbalance(a)yahoo.com> wrote:
>The other day I switched on my ASUS A7N8X Deluxe Rev 1.04 MB and got no
>video signal (yellow LED on monitor) as well as no other activity or
>indications. After removing all cards, dusting off CPU heatsink and MB,
>reseating DIMM�s and Vid card & swapping Vid card I still had the same
>indications. So I decided to remove the RTC/Setup battery and reset
>BIOS to defaults. Upon boot I got video and was able to enter the setup
>utility but as soon as I �saved any� changes I got the same indications
>as mentioned above. So I reset again, and again got video and was able
>to enter setup but was unable to �save any� BIOS settings without it
>reverting back to the �black screen of death.� I repeated it several
>more times to ensure that it was consistent, and it was.
>
>So my question is: with the indications above, can anyone tell what the
>probability is that the problem is the BIOS chip or that it�s the MB
>circuitry that supports the BIOS chip. I really don�t want to spend the
>money on the chip just to find out it�s the board.
>
>TIA,
>
>Joe
You just need to replace the CR2032 battery that is on the board. They cost
like $2.99 at walmart.

From: JBC on 9 Jun 2010 14:55
GMAN wrote:
> In article <149ce$4c0fd9e9$4831ece8$26365(a)FUSE.NET>, JBC <spheresofbalance(a)yahoo.com> wrote:
>> The other day I switched on my ASUS A7N8X Deluxe Rev 1.04 MB and got no
>> video signal (yellow LED on monitor) as well as no other activity or
>> indications. After removing all cards, dusting off CPU heatsink and MB,
>> reseating DIMM�s and Vid card & swapping Vid card I still had the same
>> indications. So I decided to remove the RTC/Setup battery and reset
>> BIOS to defaults. Upon boot I got video and was able to enter the setup
>> utility but as soon as I �saved any� changes I got the same indications
>> as mentioned above. So I reset again, and again got video and was able
>> to enter setup but was unable to �save any� BIOS settings without it
>> reverting back to the �black screen of death.� I repeated it several
>> more times to ensure that it was consistent, and it was.
>>
>> So my question is: with the indications above, can anyone tell what the
>> probability is that the problem is the BIOS chip or that it�s the MB
>> circuitry that supports the BIOS chip. I really don�t want to spend the
>> money on the chip just to find out it�s the board.
>>
>> TIA,
>>
>> Joe
> You just need to replace the CR2032 battery that is on the board. They cost
> like $2.99 at walmart.
>
Thanks,

But I don't think so. In my 16 years of building IBM clones, I've never
seen a MB whose BIOS wouldn't save data just because the "Battery
backup" was dead; which is all that battery does. It's there just in
case you loose AC power so you don't loose all your BIOS settings. A
capacitor actually keeps the BIOS settings while you have AC power. If
you loose AC power that battery takes over until such time that AC power
is restored.

Thanks anyway.

Joe
From: Steve on 9 Jun 2010 16:59
In article <4062b$4c0fe379$4831ece8$24774(a)FUSE.NET>,
spheresofbalance(a)yahoo.com says...
>
> GMAN wrote:
<snip>
> > You just need to replace the CR2032 battery that is on the board. They cost
> > like $2.99 at walmart.
> >
> Thanks,
>
> But I don't think so. In my 16 years of building IBM clones, I've never
> seen a MB whose BIOS wouldn't save data just because the "Battery
> backup" was dead;
<snip>

In my 26 years of working on PCs and their clones; I have. So you can
swap out the battery with a known good one and prove us wrong, or
have a working motherboard.

>
> Joe






s
From: Paul on 9 Jun 2010 17:11
JBC wrote:
> GMAN wrote:
>> In article <149ce$4c0fd9e9$4831ece8$26365(a)FUSE.NET>, JBC
>> <spheresofbalance(a)yahoo.com> wrote:
>>> The other day I switched on my ASUS A7N8X Deluxe Rev 1.04 MB and got
>>> no video signal (yellow LED on monitor) as well as no other activity
>>> or indications. After removing all cards, dusting off CPU heatsink
>>> and MB, reseating DIMM�s and Vid card & swapping Vid card I still had
>>> the same indications. So I decided to remove the RTC/Setup battery
>>> and reset BIOS to defaults. Upon boot I got video and was able to
>>> enter the setup utility but as soon as I �saved any� changes I got
>>> the same indications as mentioned above. So I reset again, and again
>>> got video and was able to enter setup but was unable to �save any�
>>> BIOS settings without it reverting back to the �black screen of
>>> death.� I repeated it several more times to ensure that it was
>>> consistent, and it was.
>>>
>>> So my question is: with the indications above, can anyone tell what
>>> the probability is that the problem is the BIOS chip or that it�s the
>>> MB circuitry that supports the BIOS chip. I really don�t want to
>>> spend the money on the chip just to find out it�s the board.
>>>
>>> TIA,
>>>
>>> Joe
>> You just need to replace the CR2032 battery that is on the board. They
>> cost like $2.99 at walmart.
>>
> Thanks,
>
> But I don't think so. In my 16 years of building IBM clones, I've never
> seen a MB whose BIOS wouldn't save data just because the "Battery
> backup" was dead; which is all that battery does. It's there just in
> case you loose AC power so you don't loose all your BIOS settings. A
> capacitor actually keeps the BIOS settings while you have AC power. If
> you loose AC power that battery takes over until such time that AC power
> is restored.
>
> Thanks anyway.
>
> Joe

That would depend on whether there was damage to the dual ORing diode
feeding 3V to the Southbridge. If the path from +5VSB/3VSB is burned out,
you'd be dependent on the battery. The diode is sometimes damaged
by using the "clear CMOS" jumper and leaving the power on the
computer running.

As an example, download this document and look at page 18. If diode
D2 is burned, then you're dependent on the CMOS battery and D3, to
save settings. Many motherboards in the past, would short node JP17
to ground, as a way to "clear CMOS", as an example of a way that
diode D2 can be burned if the computer power is left on. On
modern computers, both of those diodes are housed in a three pin
package that looks like a SMT transistor. The burned dual diode can be
burned bad enough, that you can't read the part number off of it,
to order a replacement.

http://www.intel.com/design/chipsets/designex/BXDPDG10.htm

There was a serious bug with those motherboards, in that saving settings
could result in the motherboard never posting again.

http://www.nforcershq.com/forum/image-vp32049.html

But your symptoms don't match that bug, as you're able to recover.
My theory is far-fetched, and I don't have any other suggestions as
to why settings could not be saved in the CMOS 256 byte RAM block.
You'd think, in any case, the motherboard would compute the checksum
on the CMOS block (no matter what state it is in), and figure out it
was corrupted, and return everything to default settings again. It
shouldn't really black screen, unless the checksum is correct by accident,
and the BIOS "eats" the bad settings.

If you have a magnifying glass, the dual diode typically has a marking
of "K45" on top, and should be located in the neighborhood of the battery.

Other places to look for a symptom match, would be these forums

http://vip.asus.com/forum/topic.aspx?board_id=1&model=A7N8X+Deluxe&SLanguage=en-us

or some of the nforcershq.com postings might help. This site has a
glossy new GUI... the downside, is it's harder to find the posts
for the older motherboards.

http://www.nforcershq.com/forum/post562671.html#p562671

Paul
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