Computer won't boot up - mobo?

I built a system for a friend about three months ago (all components brand
new at that time) and it won't boot up now. When the button is pressed,
everything "comes to life" as you would expect, ie, ATX PSU fan, CPU fan,
case fan and hard drive all spin up but two or three seconds later it all
shuts down. It never even gets as far as POST - it literally is no more than
two or three seconds before it shuts down.

I've disconnected everything I can - hard drive, DVD drive, case fan,
keyboard, mouse, monitor, speakers and even taken out the RAM (motherboard
has integrated VGA and sound so can't remove those cards) so that all that's
left is the PSU feeding the mobo/cpu (and it's fan of course), but it still
happens. Using one of these ATX PSU testers:

http://www.quietpc.com/gb-en-gbp/pro...s/x-psu-tester shows
the following values:

+5V = 5.3, +12V1 = 12.5, +3.3V = 3.3, -12V = 12.0, +12V2 = 12.3, 5VSB = 5.1,
and PG = 290ms

which all looks OK to me. Interestingly, I can leave the PSU connected to
the tester for 5 minutes or more and those readings hold steady - it's only
when I connect the PSU back to the motherboard that it cuts out within 2 or
3 seconds.

Given my limited knowledge of these things, I reckon I've proved it to be a
motherboard problem and I should now send it back to ebuyer.com for a
replacement under warranty - but am I correct or should I try anything else?

Mobo is a Gigabyte GA-MA69VM-S2

TIA,

Pete

Pete Zahut wrote:
I built a system for a friend about three months ago (all
components
brand new at that time) and it won't boot up now. When the
button is
pressed, everything "comes to life" as you would expect, ie,
ATX PSU
fan, CPU fan, case fan and hard drive all spin up but two or
three
seconds later it all shuts down. It never even gets as far as
POST -
it literally is no more than two or three seconds before it
shuts
down.
I've disconnected everything I can - hard drive, DVD drive,
case fan,
keyboard, mouse, monitor, speakers and even taken out the RAM
(motherboard has integrated VGA and sound so can't remove those
cards) so that all that's left is the PSU feeding the mobo/cpu
(and
it's fan of course), but it still happens. Using one of these
ATX PSU
testers:
http://www.quietpc.com/gb-en-gbp/pro...s/x-psu-tester
shows the following values:

+5V = 5.3, +12V1 = 12.5, +3.3V = 3.3, -12V = 12.0, +12V2 =
12.3, 5VSB
= 5.1, and PG = 290ms

which all looks OK to me. Interestingly, I can leave the PSU
connected to the tester for 5 minutes or more and those
readings hold
steady - it's only when I connect the PSU back to the
motherboard
that it cuts out within 2 or 3 seconds.

Given my limited knowledge of these things, I reckon I've
proved it
to be a motherboard problem and I should now send it back to
ebuyer.com for a replacement under warranty - but am I correct
or
should I try anything else?
Mobo is a Gigabyte GA-MA69VM-S2

Have you timed the interval between power-on and power-down? If
it's 4 seconds instead of "2 or 3 seconds", it's probable that
the power switch is stuck in the ON position, at least for some
time after you've pressed it.

To check: Pull out the power switch connector from the
motherboard and test it with a multimeter. OR, turn on the
computer by momentarily shorting the pins on the mobo with a
screwdriver blade and see if it stays on.

"Pete Zahut" dont@bother wrote in message
...
I built a system for a friend about three months ago (all components brand
new at that time) and it won't boot up now. When the button is pressed,
everything "comes to life" as you would expect, ie, ATX PSU fan, CPU fan,
case fan and hard drive all spin up but two or three seconds later it all
shuts down. It never even gets as far as POST - it literally is no more
than two or three seconds before it shuts down.

I've disconnected everything I can - hard drive, DVD drive, case fan,
keyboard, mouse, monitor, speakers and even taken out the RAM (motherboard
has integrated VGA and sound so can't remove those cards) so that all
that's left is the PSU feeding the mobo/cpu (and it's fan of course), but
it still happens. Using one of these ATX PSU testers:

http://www.quietpc.com/gb-en-gbp/pro...s/x-psu-tester shows
the following values:

+5V = 5.3, +12V1 = 12.5, +3.3V = 3.3, -12V = 12.0, +12V2 = 12.3, 5VSB =
5.1, and PG = 290ms

which all looks OK to me. Interestingly, I can leave the PSU connected to
the tester for 5 minutes or more and those readings hold steady - it's
only when I connect the PSU back to the motherboard that it cuts out
within 2 or 3 seconds.

Given my limited knowledge of these things, I reckon I've proved it to be
a motherboard problem and I should now send it back to ebuyer.com for a
replacement under warranty - but am I correct or should I try anything
else?

Mobo is a Gigabyte GA-MA69VM-S2

TIA,

Pete


Sounds like the PC is shutting down because the cpu is getting very hot,
very quickly. Be sure the heat sink is actually contacting the cpu.
Believe some motherboards with onboard video do similar if the video chip
overheats, these usually have their own fan/heat sink combo.
--
Dave

CDOs are how we got here.
A modified version, new taxes in the future, is how Congress will get us
out?

Pete Zahut wrote:
I built a system for a friend about three months ago (all components brand
new at that time) and it won't boot up now. When the button is pressed,
everything "comes to life" as you would expect, ie, ATX PSU fan, CPU fan,
case fan and hard drive all spin up but two or three seconds later it all
shuts down. It never even gets as far as POST - it literally is no more than
two or three seconds before it shuts down.

I've disconnected everything I can - hard drive, DVD drive, case fan,
keyboard, mouse, monitor, speakers and even taken out the RAM (motherboard
has integrated VGA and sound so can't remove those cards) so that all that's
left is the PSU feeding the mobo/cpu (and it's fan of course), but it still
happens. Using one of these ATX PSU testers:

http://www.quietpc.com/gb-en-gbp/pro...s/x-psu-tester shows
the following values:

+5V = 5.3, +12V1 = 12.5, +3.3V = 3.3, -12V = 12.0, +12V2 = 12.3, 5VSB = 5.1,
and PG = 290ms

which all looks OK to me. Interestingly, I can leave the PSU connected to
the tester for 5 minutes or more and those readings hold steady - it's only
when I connect the PSU back to the motherboard that it cuts out within 2 or
3 seconds.

Given my limited knowledge of these things, I reckon I've proved it to be a
motherboard problem and I should now send it back to ebuyer.com for a
replacement under warranty - but am I correct or should I try anything else?

Mobo is a Gigabyte GA-MA69VM-S2

TIA,

Pete



Check the clip on the CPU heatsink. If you're using an Arctic Cooling
heatsink, the clip may have snapped off the plastic tab. The heatsink is
now loose.

Paul

On Wed, 25 Feb 2009 12:53:18 -0000, "Pete Zahut"
dont@bother wrote:

I built a system for a friend about three months ago (all components brand
new at that time) and it won't boot up now. When the button is pressed,
everything "comes to life" as you would expect, ie, ATX PSU fan, CPU fan,
case fan and hard drive all spin up but two or three seconds later it all
shuts down. It never even gets as far as POST - it literally is no more than
two or three seconds before it shuts down.

I've disconnected everything I can - hard drive, DVD drive, case fan,
keyboard, mouse, monitor, speakers and even taken out the RAM (motherboard
has integrated VGA and sound so can't remove those cards) so that all that's
left is the PSU feeding the mobo/cpu (and it's fan of course), but it still
happens. Using one of these ATX PSU testers:

http://www.quietpc.com/gb-en-gbp/pro...s/x-psu-tester shows
the following values:

+5V = 5.3, +12V1 = 12.5, +3.3V = 3.3, -12V = 12.0, +12V2 = 12.3, 5VSB = 5.1,
and PG = 290ms

which all looks OK to me. Interestingly, I can leave the PSU connected to
the tester for 5 minutes or more and those readings hold steady - it's only
when I connect the PSU back to the motherboard that it cuts out within 2 or
3 seconds.

Given my limited knowledge of these things, I reckon I've proved it to be a
motherboard problem and I should now send it back to ebuyer.com for a
replacement under warranty - but am I correct or should I try anything else?

Mobo is a Gigabyte GA-MA69VM-S2

TIA,

Pete


In addition to what others wrote, that PSU tester you have
cannot validate a PSU as working properly, it can only
indicate if a PSU isn't working properly, sometimes.

The issue is one of loading, the tester is unlikely to put
much of a load on the rails so some designs could shut off
due to this, and the flip-side is since it doesn't put
either the PSU's rated max load on it or even the
anticipated load the system causes, you have no indication
if the PSU can operate at the required output level and
rise-times needed in a modern system.

I mention these things partly because there is still quite a
good chance the PSU itself is shutting off. It is common
when that happens, to need unplug the system from AC power
to reset the PSU, but it could be that some PSU won't need
this to happen. If possible it would be good to try and
monitor the voltage with a multimeter while in the turn-on,
auto-turn-off fault to see if the voltages are getting out
of spec at that point.

If they are not, then I would be more comfortable assuming
the motherboard is bad, although if you are running out of
time as a window of opportunity to get a replacement under
warranty, it could be better to go ahead even if it turns
out to not be the problem and so you're out the shipping
cost to return it if applicable.

Also unplug all parts non-essential to getting it to post,
leaving only video card, CPU, heatsink/fan, and one memory
module. You might need to pull AC power and clear CMOS at
that point.

Agree with Anna. The very first thing to try is to swap the PSU to a known working
one. If same issue occurs with that then I suspect the MOBO

--
Peter

Please Reply to Newsgroup for the benefit of others
Requests for assistance by email can not and will not be acknowledged.

"Pete Zahut" dont@bother wrote in message
...
I built a system for a friend about three months ago (all components brand new at
that time) and it won't boot up now. When the button is pressed, everything "comes
to life" as you would expect, ie, ATX PSU fan, CPU fan, case fan and hard drive all
spin up but two or three seconds later it all shuts down. It never even gets as far
as POST - it literally is no more than two or three seconds before it shuts down.

I've disconnected everything I can - hard drive, DVD drive, case fan, keyboard,
mouse, monitor, speakers and even taken out the RAM (motherboard has integrated
VGA and sound so can't remove those cards) so that all that's left is the PSU
feeding the mobo/cpu (and it's fan of course), but it still happens. Using one of
these ATX PSU testers:

http://www.quietpc.com/gb-en-gbp/pro...s/x-psu-tester shows the
following values:

+5V = 5.3, +12V1 = 12.5, +3.3V = 3.3, -12V = 12.0, +12V2 = 12.3, 5VSB = 5.1, and
PG = 290ms

which all looks OK to me. Interestingly, I can leave the PSU connected to the
tester for 5 minutes or more and those readings hold steady - it's only when I
connect the PSU back to the motherboard that it cuts out within 2 or 3 seconds.

Given my limited knowledge of these things, I reckon I've proved it to be a
motherboard problem and I should now send it back to ebuyer.com for a replacement
under warranty - but am I correct or should I try anything else?

Mobo is a Gigabyte GA-MA69VM-S2

TIA,

Pete

Peter Foldes wrote:
Agree with Anna. The very first thing to try is to swap the PSU to a
known working one. If same issue occurs with that then I suspect the
MOBO

"Pete Zahut" dont@bother wrote in message
...
I built a system for a friend about three months ago (all components
brand new at that time) and it won't boot up now. When the button is
pressed, everything "comes to life" as you would expect, ie, ATX PSU
fan, CPU fan, case fan and hard drive all spin up but two or three
seconds later it all shuts down. It never even gets as far as POST -
it literally is no more than two or three seconds before it shuts
down. I've disconnected everything I can - hard drive, DVD drive, case
fan, keyboard, mouse, monitor, speakers and even taken out the RAM
(motherboard has integrated VGA and sound so can't remove those
cards) so that all that's left is the PSU feeding the mobo/cpu (and
it's fan of course), but it still happens. Using one of these ATX
PSU testers:
http://www.quietpc.com/gb-en-gbp/pro...s/x-psu-tester
shows the following values:

+5V = 5.3, +12V1 = 12.5, +3.3V = 3.3, -12V = 12.0, +12V2 = 12.3,
5VSB = 5.1, and PG = 290ms

which all looks OK to me. Interestingly, I can leave the PSU
connected to the tester for 5 minutes or more and those readings
hold steady - it's only when I connect the PSU back to the
motherboard that it cuts out within 2 or 3 seconds. Given my limited
knowledge of these things, I reckon I've proved it
to be a motherboard problem and I should now send it back to
ebuyer.com for a replacement under warranty - but am I correct or
should I try anything else? Mobo is a Gigabyte GA-MA69VM-S2

OK, so now I'm officially confused (yeah, right - like I wasn't before) )

I'm tagging my reply on to Peter's message because it's the last one in the
thread that I can see and I'm going to touch on almost everything that
everyone has suggested.

Used a multimeter to test the on/off button like pimpom suggested, tests
OK - contact when button pressed, open circuit when button released.

Lil' Dave/Paul - CPU heatsink well seated and tight up to CPU so no
overheating issues.

Kony/Anna/Peter - not measured voltages because (at that time anyway) the
motherboard was still in the case and it was very difficult to get the
probes into the connector. I did disconnect all drives, case fan, etc., etc
apart from graphics and sound (couldn't do anything about these as they are
integrated on the motherboard) and it was still shutting down after 2 to 3
seconds.

Now the interesting and most confusing bit )

Substituted the PSU for a known good one and problem still there. I got a
bit enthusiastic then and forgot about Kony's suggestion about testing the
voltages and went for my own initial diagnosis of faulty motherboard (and it
was seemingly backed up by Anna's posting) so I set about getting the board
out of the case.

Don't know what made me do it but I suddenly thought that I'd get the other
stuff (HDD, Floppy etc) out of the case, build the components up on the
bench and give it a last try, just to again reassure myself that it was the
motherboard (and now I had easy access to the connectors to check the
voltages).

Lo and behold, the darn thing is working perfectly now, both with the old
and new PSUs!!!!

All voltages are within specs (as they would be now that it's working) and
the fault has just disappeared - which I know just can't be true and isn't
right because faults don't just fix themselves - but it has.

Said I was confused! I'll leave it running on the bench overnight and see
what happens but meantime, anyone shed any light?

Thanks,

Pete

On Wed, 25 Feb 2009 22:27:57 -0000, "Pete Zahut"
dont@bother wrote:

I did disconnect all drives, case fan, etc., etc
apart from graphics and sound (couldn't do anything about these as they are
integrated on the motherboard) and it was still shutting down after 2 to 3
seconds.

Now the interesting and most confusing bit )

Substituted the PSU for a known good one and problem still there. I got a
bit enthusiastic then and forgot about Kony's suggestion about testing the
voltages and went for my own initial diagnosis of faulty motherboard (and it
was seemingly backed up by Anna's posting) so I set about getting the board
out of the case.

Don't know what made me do it but I suddenly thought that I'd get the other
stuff (HDD, Floppy etc) out of the case, build the components up on the
bench and give it a last try, just to again reassure myself that it was the
motherboard (and now I had easy access to the connectors to check the
voltages).

Lo and behold, the darn thing is working perfectly now, both with the old
and new PSUs!!!!

All voltages are within specs (as they would be now that it's working) and
the fault has just disappeared - which I know just can't be true and isn't
right because faults don't just fix themselves - but it has.

Said I was confused! I'll leave it running on the bench overnight and see
what happens but meantime, anyone shed any light?

Thanks,

Pete


Possibly a case standoff installed where there shouldn't be
one, or something else causing a short? Just grabbing at
straws, possibly the board has a broken solder joint(s) or
cracks in it and the different orientation or not being
screwed down has caused these broken part(s) of a circuit to
temporarily be continuous again.

kony wrote:
On Wed, 25 Feb 2009 22:27:57 -0000, "Pete Zahut"
dont@bother wrote:

I did disconnect all drives, case fan, etc., etc
apart from graphics and sound (couldn't do anything about these as
they are integrated on the motherboard) and it was still shutting
down after 2 to 3 seconds.

Now the interesting and most confusing bit )

Substituted the PSU for a known good one and problem still there. I
got a bit enthusiastic then and forgot about Kony's suggestion about
testing the voltages and went for my own initial diagnosis of faulty
motherboard (and it was seemingly backed up by Anna's posting) so I
set about getting the board out of the case.

Don't know what made me do it but I suddenly thought that I'd get
the other stuff (HDD, Floppy etc) out of the case, build the
components up on the bench and give it a last try, just to again
reassure myself that it was the motherboard (and now I had easy
access to the connectors to check the voltages).

Lo and behold, the darn thing is working perfectly now, both with
the old and new PSUs!!!!

All voltages are within specs (as they would be now that it's
working) and the fault has just disappeared - which I know just
can't be true and isn't right because faults don't just fix
themselves - but it has.

Said I was confused! I'll leave it running on the bench overnight
and see what happens but meantime, anyone shed any light?

Thanks,

Pete


Possibly a case standoff installed where there shouldn't be
one, or something else causing a short? Just grabbing at
straws, possibly the board has a broken solder joint(s) or
cracks in it and the different orientation or not being
screwed down has caused these broken part(s) of a circuit to
temporarily be continuous again.

You could well be right Kony, I'll have to see what happens when I put
everything back in the case again. It's now been running a burn-in program
for the last 12 hours without any problems so I'll take this opportunity to
say thanks very much to all who replied and offered help - much appreciated.

Pete

Pete Zahut wrote:
kony wrote:

.... snip ...

Possibly a case standoff installed where there shouldn't be
one, or something else causing a short? Just grabbing at
straws, possibly the board has a broken solder joint(s) or
cracks in it and the different orientation or not being
screwed down has caused these broken part(s) of a circuit to
temporarily be continuous again.

You could well be right Kony, I'll have to see what happens
when I put everything back in the case again. It's now been
running a burn-in program for the last 12 hours without any
problems so I'll take this opportunity to say thanks very much
to all who replied and offered help - much appreciated.

No. First examine (with great care) all the areas where standoffs
touch the mother board, and examine the mounting screws too. They
may need insulating washers.

--
[mail]: Chuck F (cbfalconer at maineline dot net)
[page]: http://cbfalconer.home.att.net
Try the download section.