A7N8X--Green led only and no fans

Ruben

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Apr 20, 2004
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I was going about fine today when my computer died.
I have green led on mobo (no AGP WARNING led) and +5.0V comming out of
the power supply (an old 250 Watts). After clearing the cmos twice and
shorting the PWR connector with a jumper, I still have nothing!
No fans, not a bip, nothing!

Could it be my Power Supply or I have a dead mobo?
What else can I try?
By the way this is after 1 1/2 years of great use!
 

Paul

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Mar 30, 2004
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In article <1106603251.372804.179930@f14g2000cwb.googlegroups.com>,
ruben@cae.com wrote:

> I was going about fine today when my computer died.
> I have green led on mobo (no AGP WARNING led) and +5.0V comming out of
> the power supply (an old 250 Watts). After clearing the cmos twice and
> shorting the PWR connector with a jumper, I still have nothing!
> No fans, not a bip, nothing!
>
> Could it be my Power Supply or I have a dead mobo?
> What else can I try?
> By the way this is after 1 1/2 years of great use!

You should swap the power supply first. Power supplies are
a frequent cause of trouble, and are more likely to die, than
a processor or a motherboard.

The two power switch pins on the PANEL header, are intended
for momentary contact, not the continuous contact if you left
the jumper on there. It is "touch" for a fraction of a second
to switch on, and "hold" for up to four seconds, to guarantee
it turns off. I use a slot head screwdriver tip to do this
(but drain static charge off the screwdriver tip, before touching
it to the power pins).

Are the fans spinning ? A spinning fan means the +12V is
working to some degree.

Paul
 

Ruben

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Apr 20, 2004
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Hi Paul;
Thanks for your prompt response!
I closed the power pins for a very short time with a jumper--I am aware
that this is a momentary connection.

Now, green led means that your +5.0V is fine (as verfified also with a
voltmeter) Once I close the PWR pins I get absolutely NADA! No fans,
nothing. Therefore I cannot determine if the power supply +/- 12.0V,
-5.0V, etc, is faulty, or if the motherboard stopped sensing my PWR to
tell my P/S to enable the rest of the power rails.

I will get a new and stronger P/S, remove each card (video, sound,
SCSI, etc) and try it like that.

I don't think is the CPU, though--what do you think?

Thanks;


Paul wrote:
> In article <1106603251.372804.179930@f14g2000cwb.googlegroups.com>,
> ruben@cae.com wrote:
>
> > I was going about fine today when my computer died.
> > I have green led on mobo (no AGP WARNING led) and +5.0V comming out
of
> > the power supply (an old 250 Watts). After clearing the cmos twice
and
> > shorting the PWR connector with a jumper, I still have nothing!
> > No fans, not a bip, nothing!
> >
> > Could it be my Power Supply or I have a dead mobo?
> > What else can I try?
> > By the way this is after 1 1/2 years of great use!
>
> You should swap the power supply first. Power supplies are
> a frequent cause of trouble, and are more likely to die, than
> a processor or a motherboard.
>
> The two power switch pins on the PANEL header, are intended
> for momentary contact, not the continuous contact if you left
> the jumper on there. It is "touch" for a fraction of a second
> to switch on, and "hold" for up to four seconds, to guarantee
> it turns off. I use a slot head screwdriver tip to do this
> (but drain static charge off the screwdriver tip, before touching
> it to the power pins).
>
> Are the fans spinning ? A spinning fan means the +12V is
> working to some degree.
>
> Paul
 

Paul

Splendid
Mar 30, 2004
5,267
0
25,780
Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

In article <1106657053.467101.92660@z14g2000cwz.googlegroups.com>,
ruben@cae.com wrote:

> Hi Paul;
> Thanks for your prompt response!
> I closed the power pins for a very short time with a jumper--I am aware
> that this is a momentary connection.
>
> Now, green led means that your +5.0V is fine (as verfified also with a
> voltmeter) Once I close the PWR pins I get absolutely NADA! No fans,
> nothing. Therefore I cannot determine if the power supply +/- 12.0V,
> -5.0V, etc, is faulty, or if the motherboard stopped sensing my PWR to
> tell my P/S to enable the rest of the power rails.
>
> I will get a new and stronger P/S, remove each card (video, sound,
> SCSI, etc) and try it like that.
>
> I don't think is the CPU, though--what do you think?
>
> Thanks;

Yes, the green LED means the +5VSB is fine. But the +5VSB must be
steady - the green LED cannot flicker or flash. If the green LED
will not stay lit, every time the green LED goes off, so will the
main power of the supply.

Unless you can remember a specific event, where you did something
that could potentially have damaged the motherboard (like drop a
screwdriver on it, and scrape a tiny component off the motherboard),
then it is generally safe to assume the motherboard is able to
detect the momentary closure of the two PWR pins. There can be
situations, if for example, an IDE cable is only partially seated
in a motherboard IDE connector, where you'll discover the
motherboard no longer behaves normally. But if all cables haven't
been disturbed lately, and you've checked that everything is plugged
in where it is supposed to be, then a failure to start likely
means the PSU has died.

To eliminate a short of the motherboard to something, you can
do the cardboard test. You can remove the motherboard and PSU
from the chassis, and assemble them on your work table. You don't
need anything connected to the PANEL header. Plug the PSU into
the motherboard, then plug the PSU into the wall. You should be
able to momentarily touch the two PWR switch pins on the PANEL
header with a screwdriver tip, and start the board. If that
doesn't work, then I would try another power supply first. And,
if it happens not to be the power supply that has failed this
time, rest assured, you'll get to use the replacement power
supply sometime in the next couple of years anyway. (Fan
failure, capacitor failure, lightning etc.)

As you note, the "AGP warn" circuit can prevent the PWR switch
from starting the board. AFAIK, the red LED would light, if
that circuit got upset for any reason. I think "AGP warn" is
disabled, if the AGP video card is removed from the motherboard,
and there must be a pin on the video card slot that is used to
detect the presence of an AGP video card and enable the circuit.
It is possible for the "AGP warn" circuit to fail, but generally
what happens, is the red LED stays on all the time, and the
board won't start. If your red LED is off, it would take a double
failure ("AGP warn" fails and red LED fails too) to kill the
board, and that is too unlikely to contemplate. If a motherboard
survives the first week of continuous use, chances are it will
have a long life, barring a "finger problem" of some sort.

Paul

>
>
> Paul wrote:
> > In article <1106603251.372804.179930@f14g2000cwb.googlegroups.com>,
> > ruben@cae.com wrote:
> >
> > > I was going about fine today when my computer died.
> > > I have green led on mobo (no AGP WARNING led) and +5.0V comming out
> of
> > > the power supply (an old 250 Watts). After clearing the cmos twice
> and
> > > shorting the PWR connector with a jumper, I still have nothing!
> > > No fans, not a bip, nothing!
> > >
> > > Could it be my Power Supply or I have a dead mobo?
> > > What else can I try?
> > > By the way this is after 1 1/2 years of great use!
> >
> > You should swap the power supply first. Power supplies are
> > a frequent cause of trouble, and are more likely to die, than
> > a processor or a motherboard.
> >
> > The two power switch pins on the PANEL header, are intended
> > for momentary contact, not the continuous contact if you left
> > the jumper on there. It is "touch" for a fraction of a second
> > to switch on, and "hold" for up to four seconds, to guarantee
> > it turns off. I use a slot head screwdriver tip to do this
> > (but drain static charge off the screwdriver tip, before touching
> > it to the power pins).
> >
> > Are the fans spinning ? A spinning fan means the +12V is
> > working to some degree.
> >
> > Paul
 

Ruben

Distinguished
Apr 20, 2004
74
0
18,630
Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

Paul;
I had just finished connecting a new Audigy 2 to the motherboard and I
was trying to get new drivers from the Creative site when everything
died.
So, it was either that some of the contacts on the PCI slot were
shorted due to the new Audigy not being placed properly, or that this
new Audigy 2 drew to much current from my old 250W power supply and
actually killed it.

I just got myself a brand new 400W Antec PSU. I'll try the cardboard
test with this new PSU and let you know.

Thanks again;

Ruben


Paul wrote:
> In article <1106657053.467101.92660@z14g2000cwz.googlegroups.com>,
> ruben@cae.com wrote:
>
> > Hi Paul;
> > Thanks for your prompt response!
> > I closed the power pins for a very short time with a jumper--I am
aware
> > that this is a momentary connection.
> >
> > Now, green led means that your +5.0V is fine (as verfified also
with a
> > voltmeter) Once I close the PWR pins I get absolutely NADA! No
fans,
> > nothing. Therefore I cannot determine if the power supply +/-
12.0V,
> > -5.0V, etc, is faulty, or if the motherboard stopped sensing my PWR
to
> > tell my P/S to enable the rest of the power rails.
> >
> > I will get a new and stronger P/S, remove each card (video, sound,
> > SCSI, etc) and try it like that.
> >
> > I don't think is the CPU, though--what do you think?
> >
> > Thanks;
>
> Yes, the green LED means the +5VSB is fine. But the +5VSB must be
> steady - the green LED cannot flicker or flash. If the green LED
> will not stay lit, every time the green LED goes off, so will the
> main power of the supply.
>
> Unless you can remember a specific event, where you did something
> that could potentially have damaged the motherboard (like drop a
> screwdriver on it, and scrape a tiny component off the motherboard),
> then it is generally safe to assume the motherboard is able to
> detect the momentary closure of the two PWR pins. There can be
> situations, if for example, an IDE cable is only partially seated
> in a motherboard IDE connector, where you'll discover the
> motherboard no longer behaves normally. But if all cables haven't
> been disturbed lately, and you've checked that everything is plugged
> in where it is supposed to be, then a failure to start likely
> means the PSU has died.
>
> To eliminate a short of the motherboard to something, you can
> do the cardboard test. You can remove the motherboard and PSU
> from the chassis, and assemble them on your work table. You don't
> need anything connected to the PANEL header. Plug the PSU into
> the motherboard, then plug the PSU into the wall. You should be
> able to momentarily touch the two PWR switch pins on the PANEL
> header with a screwdriver tip, and start the board. If that
> doesn't work, then I would try another power supply first. And,
> if it happens not to be the power supply that has failed this
> time, rest assured, you'll get to use the replacement power
> supply sometime in the next couple of years anyway. (Fan
> failure, capacitor failure, lightning etc.)
>
> As you note, the "AGP warn" circuit can prevent the PWR switch
> from starting the board. AFAIK, the red LED would light, if
> that circuit got upset for any reason. I think "AGP warn" is
> disabled, if the AGP video card is removed from the motherboard,
> and there must be a pin on the video card slot that is used to
> detect the presence of an AGP video card and enable the circuit.
> It is possible for the "AGP warn" circuit to fail, but generally
> what happens, is the red LED stays on all the time, and the
> board won't start. If your red LED is off, it would take a double
> failure ("AGP warn" fails and red LED fails too) to kill the
> board, and that is too unlikely to contemplate. If a motherboard
> survives the first week of continuous use, chances are it will
> have a long life, barring a "finger problem" of some sort.
>
> Paul
>
> >
> >
> > Paul wrote:
> > > In article
<1106603251.372804.179930@f14g2000cwb.googlegroups.com>,
> > > ruben@cae.com wrote:
> > >
> > > > I was going about fine today when my computer died.
> > > > I have green led on mobo (no AGP WARNING led) and +5.0V comming
out
> > of
> > > > the power supply (an old 250 Watts). After clearing the cmos
twice
> > and
> > > > shorting the PWR connector with a jumper, I still have nothing!
> > > > No fans, not a bip, nothing!
> > > >
> > > > Could it be my Power Supply or I have a dead mobo?
> > > > What else can I try?
> > > > By the way this is after 1 1/2 years of great use!
> > >
> > > You should swap the power supply first. Power supplies are
> > > a frequent cause of trouble, and are more likely to die, than
> > > a processor or a motherboard.
> > >
> > > The two power switch pins on the PANEL header, are intended
> > > for momentary contact, not the continuous contact if you left
> > > the jumper on there. It is "touch" for a fraction of a second
> > > to switch on, and "hold" for up to four seconds, to guarantee
> > > it turns off. I use a slot head screwdriver tip to do this
> > > (but drain static charge off the screwdriver tip, before touching
> > > it to the power pins).
> > >
> > > Are the fans spinning ? A spinning fan means the +12V is
> > > working to some degree.
> > >
> > > Paul