No Power problem

[Guest]

Archived from groups: alt.comp.hardware.homebuilt (More info?)

Hi Folks,
I've tried to Google on this problem, all to no avail. Apologies if this is in
a FAQ here (I looked for that too).

Home-built PC. Worked fine for a couple of years.
Recently we swapped the PC to another room (and now owned by another of my kids)
and a few weeks later we heard a "tick tick tick" sound of about a two or
three second interval.
My philosophy was to leave it until there was a "hard" failure of some sort, but
the new user kept complaining about sporadic reboots.

Eventually I opened the case and discovered the source of the sound - the internal
speaker. Since the rebooting was still sporadic, I vacuumed the innards,
removed and reseated the boards and put it all back together.
Same sound, same sporadic reboots.

A few days later the rebooting became a regular occurence - on a 3-minute cycle.
Since I tried everything else, and since I just remembered that another son
had a spare power supply for his machine, I swapped that.
Result: no ticking and no rebooting!

Well, that lasted for about 3 weeks. Now it won't boot at all.
We took the new PSU and installed it in another machine, with full success.

The symptoms of the present situation are that when I press the power button
I can see the CPU fan spin for 0.5second and then go still. Prod the power
button again to no effect. Switch the computer PSU off at the mains for a
few seconds, reapply power and it all repeats.
I'm guessing that the soft-power circuitry has caused the PSU to close down
very swiftly after power up.

My guess is that the failing old PSU has damaged the motherboard - but you
folks will probably know better.

Any suggestions welcomed; thanks in advance.

Mungo Henning

 

[Guest]

Archived from groups: alt.comp.hardware.homebuilt (More info?)

Mungo Henning wrote:

> Hi Folks,
> I've tried to Google on this problem, all to no avail. Apologies if this is in
> a FAQ here (I looked for that too).
>
> Home-built PC. Worked fine for a couple of years.
> Recently we swapped the PC to another room (and now owned by another of my kids)
> and a few weeks later we heard a "tick tick tick" sound of about a two or
> three second interval.
> My philosophy was to leave it until there was a "hard" failure of some sort, but
> the new user kept complaining about sporadic reboots.
>
> Eventually I opened the case and discovered the source of the sound - the internal
> speaker.

Are you absolutely sure it came from the speaker? Because that sure sounds
like a hard drive problem. When they start to go bad they'll do clicking
sounds as they recalibrate head position after a bad sector read.


> Since the rebooting was still sporadic, I vacuumed the innards,
> removed and reseated the boards and put it all back together.
> Same sound, same sporadic reboots.
>
> A few days later the rebooting became a regular occurence - on a 3-minute cycle.

Is it running Windows 2000/XP? They default to rebooting on a critical
error. Too late now, since it won't boot, but, for future reference, you
can turn that auto reboot off (helps to see the BSOD message) and, the more
important thing, you should check the system logs to see what caused the
reboot. That might have pointed you right straight away to what was failing
before it became un-bootable (like if it was logging hard drive errors).

On the other hand, if it was a hardware fault directly causing the reboots
(e.g PSU fault), without Windows knowing about it, there would be no log
entry nor a BSOD: it would just suddenly be at the BIOS splash screen.

> Since I tried everything else, and since I just remembered that another son
> had a spare power supply for his machine, I swapped that.
> Result: no ticking and no rebooting!
>
> Well, that lasted for about 3 weeks. Now it won't boot at all.
> We took the new PSU and installed it in another machine, with full success.
>
> The symptoms of the present situation are that when I press the power button
> I can see the CPU fan spin for 0.5second and then go still. Prod the power
> button again to no effect. Switch the computer PSU off at the mains for a
> few seconds, reapply power and it all repeats.
> I'm guessing that the soft-power circuitry has caused the PSU to close down
> very swiftly after power up.

Unlikely. Soft-power shutdown is usually a 4-6 second delay, not .5
seconds, and the clicking sound prior to complete failure indicates it
isn't a 'stuck' switch, or something of that nature.

The symptom you describe indicates an overload, or short, somewhere that
kicks in the power supply's over-current protection and once OCP kicks in
you have to remove power to clear it, which is why it takes the mains
switch cycle.

>
> My guess is that the failing old PSU has damaged the motherboard - but you
> folks will probably know better.

Doubtful, since it worked when the other one was swapped in but that
doesn't mean the motherboard might not have been failing of it's own
accord. A weak point on motherboards are the CPU power regulator capacitors
which, as they age (aggravated by excessive case temperature), can leak,
bulge, and become defective. That can cause erratic operation, boot
failure, and PSU overload (defective capacitor shorts the power rail out).

You can visually inspect for that. They're 'big', by comparison,
'cylinders' around the CPU socket area. The tops, while often radially
'grooved', should be flat. If they're bulged they're bad. Also, check for
leakage on and around them.


> Any suggestions welcomed; thanks in advance.

Remove all PCI cards, unplug the hard drive(s) and CD-ROM(s), and anything
else (case fans, for example) beyond the motherboard, CPU, memory, and
video and see if it will power up. If it does then put them back in one by
one till something causes the overload again: that will be your defective
device.

If it doesn't power up bare bones then remove the video card and try power.
You won't see anything on the screen, obviously, but the point is to just
see if power will stay up; not boot. Then remove memory and try power. If
all else fails, remove the CPU and see if just the motherboard alone will
stay up.

Since I'm suspicious of the hard drive I'd pull it first and try power.


> Mungo Henning

 

[Guest]

Archived from groups: alt.comp.hardware.homebuilt (More info?)

On 15 Nov 2004 12:28:52 -0800, mungoh@despammed.com (Mungo
Henning) wrote:

>Hi Folks,
>I've tried to Google on this problem, all to no avail. Apologies if this is in
>a FAQ here (I looked for that too).
>
>Home-built PC. Worked fine for a couple of years.
>Recently we swapped the PC to another room (and now owned by another of my kids)
>and a few weeks later we heard a "tick tick tick" sound of about a two or
>three second interval.
>My philosophy was to leave it until there was a "hard" failure of some sort, but
>the new user kept complaining about sporadic reboots.
>
>Eventually I opened the case and discovered the source of the sound - the internal
>speaker. Since the rebooting was still sporadic, I vacuumed the innards,
>removed and reseated the boards and put it all back together.
>Same sound, same sporadic reboots.
>
>A few days later the rebooting became a regular occurence - on a 3-minute cycle.
>Since I tried everything else, and since I just remembered that another son
>had a spare power supply for his machine, I swapped that.
>Result: no ticking and no rebooting!
>
>Well, that lasted for about 3 weeks. Now it won't boot at all.
>We took the new PSU and installed it in another machine, with full success.
>
>The symptoms of the present situation are that when I press the power button
>I can see the CPU fan spin for 0.5second and then go still. Prod the power
>button again to no effect. Switch the computer PSU off at the mains for a
>few seconds, reapply power and it all repeats.
>I'm guessing that the soft-power circuitry has caused the PSU to close down
>very swiftly after power up.
>
>My guess is that the failing old PSU has damaged the motherboard - but you
>folks will probably know better.
>
>Any suggestions welcomed; thanks in advance.
>
>Mungo Henning

SInce the system did continue working after the first power
supply was swapped out, it seems more likley the system is
to blame, not the power (assuming these aren't just
low-capacity or quality generic power supplies that might
have high enough capacity for the system in question, but
still be sufficient for the "other" system).

Inspect the motherboard for failed capacitor... vented
(domed, leaky on top) and leaks or residue on their bottoms.

Try removing disconnecting all components except video card,
1 memory module, CPU and heatsink fan... then try powering
up again. If it succeeds, add hard drive and try booting
windows. Progressively add parts until problem resurfaces
and take voltage measurements of power, preferribly at the
ATX connector with a multimeter.

 

[Guest]

Archived from groups: alt.comp.hardware.homebuilt (More info?)

Many thanks to all who have kindly replied to me.
To save me replying to each person, I thought I'd reply to David's
post:

David Maynard <dNOTmayn@ev1.net> wrote in message news:<10pij71errs0ba4@corp.supernews.com>...
> Mungo Henning wrote:
>
> [snip]
> > Eventually I opened the case and discovered the source of the sound - the internal
> > speaker.
>
> Are you absolutely sure it came from the speaker?

Fair question. The internal piezo speaker connected to the motherboard
with
a pair of "flying lead" wires. When I disconnected either the sound
stopped.
This is pretty conclusive for me (I checked that I didn't disturb
anything
else whilst temporarily disconnecting).

> Because that sure sounds
> like a hard drive problem. When they start to go bad they'll do clicking
> sounds as they recalibrate head position after a bad sector read.

That was the worry, but I thought that a hard drive failure would be a
lot
more obvious (I come from the era of exchangable disk packs - I've
watched
engineers misdiagnose a head crash and stick a brand new spindle of
disks into a pack whose heads were already mangled... ;-)


> Is it running Windows 2000/XP? They default to rebooting on a critical
> error. Too late now, since it won't boot, but, for future reference, you
> can turn that auto reboot off (helps to see the BSOD message) and, the more
> important thing, you should check the system logs to see what caused the
> reboot. That might have pointed you right straight away to what was failing
> before it became un-bootable (like if it was logging hard drive errors).

Fair comment David. Just getting ANY power to even light a LED would
be
good just now. The machine at present consists of PSU with a single
power
lead to the motherboard and nothing else connected - all cards
removed, no
disks connected nor powered. The PSU only supplies the motherboard at
the
moment.



> Unlikely. Soft-power shutdown is usually a 4-6 second delay, not .5
> seconds, and the clicking sound prior to complete failure indicates it
> isn't a 'stuck' switch, or something of that nature.

I've even tested the (front panel) power switch with a multimeter - no
problems there.


>
> The symptom you describe indicates an overload, or short, somewhere that
> kicks in the power supply's over-current protection and once OCP kicks in
> you have to remove power to clear it, which is why it takes the mains
> switch cycle.

Sounds plausible. I'm getting to that conclusion myself.



>
> Doubtful, since it worked when the other one was swapped in but that
> doesn't mean the motherboard might not have been failing of it's own
> accord. A weak point on motherboards are the CPU power regulator capacitors
> which, as they age (aggravated by excessive case temperature), can leak,
> bulge, and become defective. That can cause erratic operation, boot
> failure, and PSU overload (defective capacitor shorts the power rail out).
>
> You can visually inspect for that. They're 'big', by comparison,
> 'cylinders' around the CPU socket area. The tops, while often radially
> 'grooved', should be flat. If they're bulged they're bad. Also, check for
> leakage on and around them.

Nothing seen: no discolouration, no bulging. I've removed the
motherboard and
inspected the reverse side - nothing seen, no scorch marks on the
case...


> Remove all PCI cards, unplug the hard drive(s) and CD-ROM(s), and anything
> else (case fans, for example) beyond the motherboard, CPU, memory, and
> video and see if it will power up. If it does then put them back in one by
> one till something causes the overload again: that will be your defective
> device.

Good old "divide and conquer" debug technique. Trouble is, power to
the
motherboard alone would be a good start! ;-)

>
> If it doesn't power up bare bones then remove the video card and try power.
> You won't see anything on the screen, obviously, but the point is to just
> see if power will stay up; not boot. Then remove memory and try power. If
> all else fails, remove the CPU and see if just the motherboard alone will
> stay up.

I'll try that later (I didn't want to powerup with the CPU in place).

Could it be that the under-the-cpu thermistor has failed and kicked
some
"crowbar" circuit into life?

I did remove the cpu for a visual inspection but again there was
nothing
obviously wrong.


Tonight I plan to try a PSU from another computer - if the symptoms
persist
then its new motherboard time.
Any good source for motherboards in the UK? It's a 1.8GHz processor
and all I
would want do is replace the board.

Thanks again to everyone.

Regards

Mungo Henning

 

[user]

Archived from groups: alt.comp.hardware.homebuilt (More info?)

The same symptom happened to me few months ago, I can only speak for my own
experience.

When I reached the point, that I have to turn off/on the PSU switch to get
the PC starts, I still hoped that can live with it. But it only lasted a few
days, then I smell the burning and the PC dead totally. I could not
determine where the burning came from.

I checked the PSU, it was fine, checked the HDs, they were fine too, so I
replaced the mother board, PC came back live again.

"Mungo Henning" <mungoh@despammed.com>
???????:e88c3d0f.0411151228.15a01869@posting.google.com...
> Hi Folks,
> I've tried to Google on this problem, all to no avail. Apologies if this
is in
> a FAQ here (I looked for that too).
>
> Home-built PC. Worked fine for a couple of years.
> Recently we swapped the PC to another room (and now owned by another of my
kids)
> and a few weeks later we heard a "tick tick tick" sound of about a two or
> three second interval.
> My philosophy was to leave it until there was a "hard" failure of some
sort, but
> the new user kept complaining about sporadic reboots.
>
> Eventually I opened the case and discovered the source of the sound - the
internal
> speaker. Since the rebooting was still sporadic, I vacuumed the innards,
> removed and reseated the boards and put it all back together.
> Same sound, same sporadic reboots.
>
> A few days later the rebooting became a regular occurence - on a 3-minute
cycle.
> Since I tried everything else, and since I just remembered that another
son
> had a spare power supply for his machine, I swapped that.
> Result: no ticking and no rebooting!
>
> Well, that lasted for about 3 weeks. Now it won't boot at all.
> We took the new PSU and installed it in another machine, with full
success.
>
> The symptoms of the present situation are that when I press the power
button
> I can see the CPU fan spin for 0.5second and then go still. Prod the power
> button again to no effect. Switch the computer PSU off at the mains for a
> few seconds, reapply power and it all repeats.
> I'm guessing that the soft-power circuitry has caused the PSU to close
down
> very swiftly after power up.
>
> My guess is that the failing old PSU has damaged the motherboard - but you
> folks will probably know better.
>
> Any suggestions welcomed; thanks in advance.
>
> Mungo Henning

 

[Guest]

Archived from groups: alt.comp.hardware.homebuilt (More info?)

Mungo Henning wrote:

> Many thanks to all who have kindly replied to me.
> To save me replying to each person, I thought I'd reply to David's
> post:
>
> David Maynard <dNOTmayn@ev1.net> wrote in message news:<10pij71errs0ba4@corp.supernews.com>...
>
>>Mungo Henning wrote:
>>
>>[snip]
>>
>>>Eventually I opened the case and discovered the source of the sound - the internal
>>>speaker.
>>
>>Are you absolutely sure it came from the speaker?
>
>
> Fair question. The internal piezo speaker connected to the motherboard
> with
> a pair of "flying lead" wires. When I disconnected either the sound
> stopped.
> This is pretty conclusive for me (I checked that I didn't disturb
> anything
> else whilst temporarily disconnecting).

Hehe. Yeah, that pretty much settles that question.

>>Because that sure sounds
>>like a hard drive problem. When they start to go bad they'll do clicking
>>sounds as they recalibrate head position after a bad sector read.
>
>
> That was the worry, but I thought that a hard drive failure would be a
> lot
> more obvious (I come from the era of exchangable disk packs - I've
> watched
> engineers misdiagnose a head crash and stick a brand new spindle of
> disks into a pack whose heads were already mangled... ;-)

Ouch. Scratch another pack, literally

>>Is it running Windows 2000/XP? They default to rebooting on a critical
>>error. Too late now, since it won't boot, but, for future reference, you
>>can turn that auto reboot off (helps to see the BSOD message) and, the more
>>important thing, you should check the system logs to see what caused the
>>reboot. That might have pointed you right straight away to what was failing
>>before it became un-bootable (like if it was logging hard drive errors).
>
>
> Fair comment David. Just getting ANY power to even light a LED would
> be
> good just now. The machine at present consists of PSU with a single
> power
> lead to the motherboard and nothing else connected - all cards
> removed, no
> disks connected nor powered. The PSU only supplies the motherboard at
> the
> moment.
>
>
>
>
>>Unlikely. Soft-power shutdown is usually a 4-6 second delay, not .5
>>seconds, and the clicking sound prior to complete failure indicates it
>>isn't a 'stuck' switch, or something of that nature.
>
>
> I've even tested the (front panel) power switch with a multimeter - no
> problems there.

You're doing a good job of covering the bases.

>>The symptom you describe indicates an overload, or short, somewhere that
>>kicks in the power supply's over-current protection and once OCP kicks in
>>you have to remove power to clear it, which is why it takes the mains
>>switch cycle.
>
>
> Sounds plausible. I'm getting to that conclusion myself.
>
>
>
>
>>Doubtful, since it worked when the other one was swapped in but that
>>doesn't mean the motherboard might not have been failing of it's own
>>accord. A weak point on motherboards are the CPU power regulator capacitors
>>which, as they age (aggravated by excessive case temperature), can leak,
>>bulge, and become defective. That can cause erratic operation, boot
>>failure, and PSU overload (defective capacitor shorts the power rail out).
>>
>>You can visually inspect for that. They're 'big', by comparison,
>>'cylinders' around the CPU socket area. The tops, while often radially
>>'grooved', should be flat. If they're bulged they're bad. Also, check for
>>leakage on and around them.
>
>
> Nothing seen: no discolouration, no bulging. I've removed the
> motherboard and
> inspected the reverse side - nothing seen, no scorch marks on the
> case...

Yeah. The overcurrent protection wouldn't let it happen. Had that problem
once on an old TV set that kept tripping the breaker. In that case, though,
I could force the breaker to stay on and the curl of smoke led me to the
defective components.

That doesn't help much with a main board because it's dern hard to bypass
the OCP and, even if you did, unless you've got surface mount equipment you
can't replace much other than the socketed CPU anyway; Exception being the
CPU (Vcore) power regulator FETs.

If all else fails and you're down to hauling it to the trash bin then
that's one last thing you can try. Snip the leads off the regulator FET(s)
and see if the PSU will stay on that way. If it does, and you're so
inclined, you could then try replacing those. I have about a 50-50 bit of
luck doing so as they sometimes take out the regulator IC at the same time
and that's back into the surface mount stuff.

>>Remove all PCI cards, unplug the hard drive(s) and CD-ROM(s), and anything
>>else (case fans, for example) beyond the motherboard, CPU, memory, and
>>video and see if it will power up. If it does then put them back in one by
>>one till something causes the overload again: that will be your defective
>>device.
>
>
> Good old "divide and conquer" debug technique.

Of course

> Trouble is, power to
> the
> motherboard alone would be a good start! ;-)

Yeah. Well, Murphy said it would be.


>>If it doesn't power up bare bones then remove the video card and try power.
>>You won't see anything on the screen, obviously, but the point is to just
>>see if power will stay up; not boot. Then remove memory and try power. If
>>all else fails, remove the CPU and see if just the motherboard alone will
>>stay up.
>
>
> I'll try that later (I didn't want to powerup with the CPU in place).
>
> Could it be that the under-the-cpu thermistor has failed and kicked
> some
> "crowbar" circuit into life?

I could imagine a failed thermistor causing a motherboard temp shutdown but
that wouldn't cause a PSU OCP trip necessitating the mains power cycle off
to reset it.

>
> I did remove the cpu for a visual inspection but again there was
> nothing
> obviously wrong.

Did you try powering the motherboard without the processor? A dead
processor can easily trip the OCP, if it fails to shorted.


> Tonight I plan to try a PSU from another computer - if the symptoms
> persist
> then its new motherboard time.
> Any good source for motherboards in the UK? It's a 1.8GHz processor
> and all I
> would want do is replace the board.

I'm not up on U.K. sources. A 1.8 Ghz what? P4? XP?

>
> Thanks again to everyone.
>
> Regards
>
> Mungo Henning

 

[Guest]

Archived from groups: alt.comp.hardware.homebuilt (More info?)

On 15 Nov 2004 12:28:52 -0800, mungoh@despammed.com (Mungo Henning)
put finger to keyboard and composed:

>Hi Folks,
>I've tried to Google on this problem, all to no avail. Apologies if this is in
>a FAQ here (I looked for that too).
>
>Home-built PC. Worked fine for a couple of years.
>Recently we swapped the PC to another room (and now owned by another of my kids)
>and a few weeks later we heard a "tick tick tick" sound of about a two or
>three second interval.
>My philosophy was to leave it until there was a "hard" failure of some sort, but
>the new user kept complaining about sporadic reboots.
>
>Eventually I opened the case and discovered the source of the sound - the internal
>speaker. Since the rebooting was still sporadic, I vacuumed the innards,
>removed and reseated the boards and put it all back together.
>Same sound, same sporadic reboots.
>
>A few days later the rebooting became a regular occurence - on a 3-minute cycle.
>Since I tried everything else, and since I just remembered that another son
>had a spare power supply for his machine, I swapped that.
>Result: no ticking and no rebooting!
>
>Well, that lasted for about 3 weeks. Now it won't boot at all.
>We took the new PSU and installed it in another machine, with full success.
>
>The symptoms of the present situation are that when I press the power button
>I can see the CPU fan spin for 0.5second and then go still. Prod the power
>button again to no effect. Switch the computer PSU off at the mains for a
>few seconds, reapply power and it all repeats.
>I'm guessing that the soft-power circuitry has caused the PSU to close down
>very swiftly after power up.
>
>My guess is that the failing old PSU has damaged the motherboard - but you
>folks will probably know better.
>
>Any suggestions welcomed; thanks in advance.
>
>Mungo Henning

I'd use a DMM to check for shorts between each of the supply rails and
ground. Remove the CPU when you do this to prevent it from giving a
false low reading. If you do find a short, then check your caps and
MOSFETs, especially in the Vcore section.

It could be that failing caps caused your initial system instability
problems, and this may have precipitated MOSFET failure(s). Just
guessing ...


- Franc Zabkar
--
Please remove one 's' from my address when replying by email.

 

[Guest]

Archived from groups: alt.comp.hardware.homebuilt (More info?)

On 16 Nov 2004 07:12:05 -0800, mungoh@despammed.com (Mungo Henning)
put finger to keyboard and composed:

>That was the worry, but I thought that a hard drive failure would be a
>lot
>more obvious (I come from the era of exchangable disk packs - I've
>watched
>engineers misdiagnose a head crash and stick a brand new spindle of
>disks into a pack whose heads were already mangled... ;-)

I used to repair these crashed drives (eg Control Data BK7 300MB).
It's not a pretty sight coming in of a morning to see a mass of metal
debris under the pack cover after a night-time head crash.


- Franc Zabkar
--
Please remove one 's' from my address when replying by email.