computer won't power up - BIOS problem?

I'm running an old 450MHz CPU on an Asus P2B motherboard. Up until
today the computer was working fine. I just got back from my Christmas
holiday, during which I left the computer unplugged while I was away -
about 10 days. I also turned off the heating in my place as well - so
the apartment got cold while I was away (I'm in Norway).

When I plugged the computer back into the wall after the holiday (not
having touched anything), I get nothing from it. No glowing LED saying
it's plugged in, and no response when pressing the power/reset
buttons.

I tried a couple of suggestions from other Google groups posts:
1. Unplugged and replugged the video card.
2. Took out the BIOS battery, cleaned the contacts.

Still no luck.

What I then tried was to just take out the BIOS battery and plug the
computer in. Doing so, all the lights come on at the front (and on the
keyboard), but nothing shows up on the screen and the computer doesn't
start to boot.

Any ideas? Is the problem a result of the battery, or the cold?

Thanks ahead of time for your help.

"Yup" wrote in message
om...
I'm running an old 450MHz CPU on an Asus P2B motherboard. Up until
today the computer was working fine. I just got back from my Christmas
holiday, during which I left the computer unplugged while I was away -
about 10 days. I also turned off the heating in my place as well - so
the apartment got cold while I was away (I'm in Norway).

When I plugged the computer back into the wall after the holiday (not
having touched anything), I get nothing from it. No glowing LED saying
it's plugged in, and no response when pressing the power/reset
buttons.

I tried a couple of suggestions from other Google groups posts:
1. Unplugged and replugged the video card.
2. Took out the BIOS battery, cleaned the contacts.

Still no luck.

What I then tried was to just take out the BIOS battery and plug the
computer in. Doing so, all the lights come on at the front (and on the
keyboard), but nothing shows up on the screen and the computer doesn't
start to boot.

Any ideas? Is the problem a result of the battery, or the cold?

Thanks ahead of time for your help.


First off you need to determine if you are getting any power out of the
power supply. When you plug in the computer and power up, do you hear
the drive whine up? Do the fans start spinning? Do you hear any beeps?
Does the Power LED glow on the system case? Do the
CapsLock-NumLock-ScrollLock LEDs flash on the keyboard? If you get none
of those, have you checked that you actually have any power at the
outlet by plugging an incandescent lamp into it? Is the computer
plugged into the outlet or into a power strip (and, if a power strip, is
it powered on and have you tested it circuit breaker and plugged a light
into it)? Is there a circuit breaker on the backside of the power
supply where you push in a button to reset it? Is there a fuse that you
can unscrew from the back of the power supply to check if it blew?

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"Yup" wrote in message
om...
I'm running an old 450MHz CPU on an Asus P2B motherboard. Up until
today the computer was working fine. I just got back from my Christmas
holiday, during which I left the computer unplugged while I was away -
about 10 days. I also turned off the heating in my place as well - so
the apartment got cold while I was away (I'm in Norway).

When I plugged the computer back into the wall after the holiday (not
having touched anything), I get nothing from it. No glowing LED saying
it's plugged in, and no response when pressing the power/reset
buttons.

I tried a couple of suggestions from other Google groups posts:
1. Unplugged and replugged the video card.
2. Took out the BIOS battery, cleaned the contacts.

Still no luck.

What I then tried was to just take out the BIOS battery and plug the
computer in. Doing so, all the lights come on at the front (and on the
keyboard), but nothing shows up on the screen and the computer doesn't
start to boot.

Any ideas? Is the problem a result of the battery, or the cold?

Thanks ahead of time for your help.

Your BIOS battery is probably dead. As your computer must be
several years old, the battery probably had just about enough energy
left keep going so long as it was kept in a warm environment, aided
by the heat produced inside the computer itself when it was in
regular use. Being left alone in a Norwegian winter for more than
a week must have done it in for good.

Some computers can boot up with a good battery or with none,
but not with a weak one. Yours came closer to booting up with
no battery than with a weak one. Just pop in a new one and set
up your BIOS.

"Zotin Khuma" wrote in message
...

"Yup" wrote in message
om...
I'm running an old 450MHz CPU on an Asus P2B motherboard. Up until
today the computer was working fine. I just got back from my
Christmas
holiday, during which I left the computer unplugged while I was
away -
about 10 days. I also turned off the heating in my place as well - so
the apartment got cold while I was away (I'm in Norway).

When I plugged the computer back into the wall after the holiday (not
having touched anything), I get nothing from it. No glowing LED
saying
it's plugged in, and no response when pressing the power/reset
buttons.

I tried a couple of suggestions from other Google groups posts:
1. Unplugged and replugged the video card.
2. Took out the BIOS battery, cleaned the contacts.

Still no luck.

What I then tried was to just take out the BIOS battery and plug the
computer in. Doing so, all the lights come on at the front (and on
the
keyboard), but nothing shows up on the screen and the computer
doesn't
start to boot.

Any ideas? Is the problem a result of the battery, or the cold?

Thanks ahead of time for your help.

Your BIOS battery is probably dead. As your computer must be
several years old, the battery probably had just about enough energy
left keep going so long as it was kept in a warm environment, aided
by the heat produced inside the computer itself when it was in
regular use. Being left alone in a Norwegian winter for more than
a week must have done it in for good.

Some computers can boot up with a good battery or with none,
but not with a weak one. Yours came closer to booting up with
no battery than with a weak one. Just pop in a new one and set
up your BIOS.




Guess I've seen a computer that wouldn't boot just because the battery
was dead. The battery is supposed to provide voltage to maintain the
values saved in the CMOS copy of the BIOS' EEPROM values when there is
no power. It isn't needed when there IS power. If you, for example,
have a computer that loses time or loses BIOS settings when you power
off, just don't power off until you get a replacement battery. If the
battery goes dead so the CMOS doesn't have sufficient voltage to retain
a *copy* of the BIOS settings, the original values get read from the
EEPROM and copied back into the CMOS table (since there is now power
after you turned on the power supply) and the machine boots.

The values were originally in the EEPROM. That's what you get when you
first power up your system. That's what got stored in the EEPROM so
there actually would be usable defaults for the mobo until whenever the
jobber happened to slap in a battery to build the machine. If you don't
want to keep the customized settings on a power up, you could leave out
the battery so the defaults get used on every power up.

The only way I could see a battery causing a problem with the CMOS table
(a copy of the table from EEPROM) would be if it wasn't dead but just
didn't have enough oompf to keep the voltage high enough to ensure the
CMOS table didn't get corrupted. Some settings might then lose their
values and you don't get what you expect. However, the BIOS from the
EEPROM gets loaded first to run its bootstrap program (there are no
programs in the CMOS copy) and it performs a CRC against the values in
the CMOS copy and compares that CRC value against the one stored in the
CMOS table. If they don't match, you get some error message telling you
the CMOS copy is corrupted and you'll have to reload the values from the
EEPROM.

If the battery were dead, the EEPROM values get copied into the CMOS and
the boot continues. If the battery is insufficient to guarantee the
values in the CMOS don't get corrupted, the CRC check detects the
corruption and alerts you (so you clear the CMOS or just remove the
battery to let the CMOS drain, and then boot without a battery until you
get around to getting one).

A dead battery won't prevent you from booting up. A failing battery
might force you to wipe a corrupted table in CMOS and reload the default
one from EEPROM, but that still doesn't prevent you from booting up.
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On Wed, 5 Jan 2005 01:06:06 -0600, "Vanguard"
see_signature wrote:


A dead battery won't prevent you from booting up. A failing battery
might force you to wipe a corrupted table in CMOS and reload the default
one from EEPROM, but that still doesn't prevent you from booting up.

Well that's true to a certain extent but not the whole
story. I've a box here right now that had an almost dead
battery earlier today. The board acted completely dead, not
even CPU fan spinning upon attempted power-on, only the
power LED glowing. I cleared CMOS to no avail w/AC power
off, and eventually pulled battery and installed a new one.
Only then did the board respond at all... was an Asus
A7V333.

On 4 Jan 2005 10:56:23 -0800, (Yup) wrote:

I'm running an old 450MHz CPU on an Asus P2B motherboard.
When I plugged the computer back into the wall after the holiday (not
having touched anything), I get nothing from it.

Try to re-seat the Cpu in the Slot
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Regards & Happy New Year Everyone, SPAJKY ®
& visit my site @ http://www.spajky.vze.com
"Tualatin OC-ed / BX-Slot1 / inaudible setup!"
E-mail AntiSpam: remove ##

"kony" wrote in message
...
On Wed, 5 Jan 2005 01:06:06 -0600, "Vanguard"
see_signature wrote:


A dead battery won't prevent you from booting up. A failing battery
might force you to wipe a corrupted table in CMOS and reload the
default
one from EEPROM, but that still doesn't prevent you from booting up.

Well that's true to a certain extent but not the whole
story. I've a box here right now that had an almost dead
battery earlier today. The board acted completely dead, not
even CPU fan spinning upon attempted power-on, only the
power LED glowing. I cleared CMOS to no avail w/AC power
off, and eventually pulled battery and installed a new one.
Only then did the board respond at all... was an Asus
A7V333.


I stand corrected. If Kony says it happens then it does. Must be that
I've been lucky and either had a good battery (it boots), a bad battery
(it boots), or a weak battery (CMOS corrupted, checksum error, remove
battery, clear CMOS, it boots, and sometime later replace the battery).

I can see corrupted values in the CMOS table preventing boot up (because
the hard drive and other devices are unknown or incorrectly
parameterized) but a clear of the CMOS should force a reload of the
defaults from the EEPROM even if that reload occurs on every boot until
you finally get around to replacing the battery. Maybe if the defaults
in the EEPROM are not usable with the current hardware configuration
then it won't boot. Defaults that are unusable? Then how could you
ever used the mobo in the first place? If the setup is good and you
replace the battery quickly enough, the values are still in the CMOS and
you boot as before. If the setup is good and you replace the battery
too slowly or leave it out, the CMOS drains and you lose its settings
which can generate a checksum, low battery, or other error, and which
forces a reload of the defaults from the EEPROM (although some let you
save your customized settings in EEPROM and its that table that gets
reloaded). If the settings in the CMOS are corrupt with a good or bad
battery, you have to clear the CMOS to get the good values from EEPROM
(i.e., you have a corrupted table, so you clear it to force a reload of
defaults into it).

Know if the Asus mobo you mentioned will boot WITHOUT a battery (i.e.,
power down, remove battery, clear CMOS, and boot without the battery)?
If it doesn't boot without a battery, did you try clearing the CMOS
(with the battery still out) and try booting again? If that worked,
will the next boot work okay? A mobo that won't boot without a battery
seems like some very wrong circuit design or a defective component.

On Wed, 5 Jan 2005 13:17:11 -0600, "Vanguard"
see_signature wrote:


A dead battery won't prevent you from booting up. A failing battery
might force you to wipe a corrupted table in CMOS and reload the
default
one from EEPROM, but that still doesn't prevent you from booting up.

Well that's true to a certain extent but not the whole
story. I've a box here right now that had an almost dead
battery earlier today. The board acted completely dead, not
even CPU fan spinning upon attempted power-on, only the
power LED glowing. I cleared CMOS to no avail w/AC power
off, and eventually pulled battery and installed a new one.
Only then did the board respond at all... was an Asus
A7V333.


snip

Know if the Asus mobo you mentioned will boot WITHOUT a battery (i.e.,
power down, remove battery, clear CMOS, and boot without the battery)?
If it doesn't boot without a battery, did you try clearing the CMOS
(with the battery still out) and try booting again? If that worked,
will the next boot work okay? A mobo that won't boot without a battery
seems like some very wrong circuit design or a defective component.

Well I still have the old battery, still have the board out
too, will try that.

The history of the board was that it was working fine when
shipped to a customer, it sat unpowered (& disconnected from
AC) for about 2 weeeks AFAIK. Customer then proceeded to
try board, couldn't get it working, and since I didn't feel
comfortable telling this customer to do any troubleshooting
on it, I simply sent a replacement board. Customer returned
the A7V333, which I might've tried upon receipt but I can't
recall it now. Months(?) later I was disassembling another
testbed and decided it was convenient to swap in the A7V333
and found it odd that there was no sign of life at all...
except that power LED, but I meant the onboard 5VSB LED, not
the case power LED.

Board consistently posts and boots DOS so I'll swap the
batteries around and report back.

On Thu, 06 Jan 2005 01:00:25 GMT, kony
wrote:


Board consistently posts and boots DOS so I'll swap the
batteries around and report back.

I've checked that A7V333...

AC power disconnected, battery pulled - Acts dead, no post
(next step, seconds later) AC disconnected, CMOS cleared -
Acts dead, no post

Checked voltage on old battery, only a few dozem mV.
Reinstalled dead battery just for heck of it - no change,
still dead

Pulled batery, cleared CMOS again w/ac-off, still nothing
w/o battery

Reinstall good battery - 1st time system posts since point
when battery was removed

"kony" wrote in message
...
On Thu, 06 Jan 2005 01:00:25 GMT, kony
wrote:


Board consistently posts and boots DOS so I'll swap the
batteries around and report back.

I've checked that A7V333...

AC power disconnected, battery pulled - Acts dead, no post
(next step, seconds later) AC disconnected, CMOS cleared -
Acts dead, no post

Checked voltage on old battery, only a few dozem mV.
Reinstalled dead battery just for heck of it - no change,
still dead

Pulled batery, cleared CMOS again w/ac-off, still nothing
w/o battery

Reinstall good battery - 1st time system posts since point
when battery was removed



No battery, CMOS cleared, and it won't boot (presumably that means you
can't even get as far as to the BIOS setup screens)? Christ. Not good,
not good at all.

Hmm, does this have those fat boxes with the RTC and memory circuit
inside, like the Dallas box? The picture (even when exploded) at
http://usa.asus.com/prog/spec.asp?m=A7V333&langs=09# is too tiny for me
to see what's on that mobo. That had a memory circuit, crystal, and
tiny battery inside. Maybe the battery inside that NVRAM box is dead (I
never liked that they called it NVRAM because it had a battery inside so
the RAM really wasn't non-volatile just because the battery was hidden).
I recall you could pop off the cover to look inside.

Of the other posts found where A7V333 owners couldn't boot without the
battery, some mentioned that they were replacing their coin cell battery
every 2 to 4 months. I know a circuit to build that can use a cheap
cordless telephone 3.6V Nicad battery, 1n4001 diode, and 10-ohm, 1/4W
resistor that can be used which has the nicad recharging and takes the
place of the battery so you get around the problem of repeatedly having
to replace the battery at short intervals. But that the problem even
exists points to a defective component that is drawing too much current
from the battery (which has no recharge circuit so they just keep
draining). Of course, you would actually have to be the user of that
mobo to know after a long time if that mobo was eating up batteries
every few months instead of lasting 3 to 7 years.

Time to throw some more batteries into the toolkit, I guess.

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