Stronge symptom: non-fan his that is responsive to mouse scroll

Hi guys,

I've got a problem I've not encountered before. I was given a 4-5 year
old PC to have a tinker with and the amount of dust in it was ungodly.
It had killed the video card fan, but a capacitor on the card was
already bulging and leaking so I replaced the card. Unfortunately,
there's still this hissing sound. I've stopped all the fans, even the
new graphics card one, one at a time to see if they were related -
they're not the cause. Then, while the side panel was off, I noticed
that when I scrolled with the mouse the hiss would fluctuate with each
notch on the mouse wheel! I can repeat this and it only occurs when a
window is actually scrolling, not when you just use the mouse wheel.
Does anyone have any ideas what this could be? The tops of the caps on
the mainboard all look good, and the sound is so noticeable even with
the case closed I'd imagine if it was a venting capacitor it would've
burnt out by now. I'm out of ideas! argh!

TIA,

Ari

--
spammage trappage: remove the underscores to reply
Many people around the world are waiting for a marrow transplant. Please
volunteer to be a marrow donor and literally save someone's life:
http://www.abmdr.org.au/
http://www.marrow.org/

On 12/06/2010 3:59 PM, spodosaurus wrote:
Hi guys,

I've got a problem I've not encountered before. I was given a 4-5 year
old PC to have a tinker with and the amount of dust in it was ungodly.
It had killed the video card fan, but a capacitor on the card was
already bulging and leaking so I replaced the card. Unfortunately,
there's still this hissing sound. I've stopped all the fans, even the
new graphics card one, one at a time to see if they were related -
they're not the cause. Then, while the side panel was off, I noticed
that when I scrolled with the mouse the hiss would fluctuate with each
notch on the mouse wheel! I can repeat this and it only occurs when a
window is actually scrolling, not when you just use the mouse wheel.
Does anyone have any ideas what this could be? The tops of the caps on
the mainboard all look good, and the sound is so noticeable even with
the case closed I'd imagine if it was a venting capacitor it would've
burnt out by now. I'm out of ideas! argh!

TIA,

Ari


Okay, a bit more information: the his fluctuates (starts stops rapidly)
when the computer is processing - such as installing the ATI catalyst
pack. It's not DVDROM noise, and it's not HDD noise. When checking the
properties to check files sizes on a large group of folders the hard
drive makes it's noises but the hiss barely wavers. I'm starting to
think it's a capacitor again...


--
spammage trappage: remove the underscores to reply
Many people around the world are waiting for a marrow transplant. Please
volunteer to be a marrow donor and literally save someone's life:
http://www.abmdr.org.au/
http://www.marrow.org/

On Sat, 12 Jun 2010 16:15:04 +0800, spodosaurus wrote:

On 12/06/2010 3:59 PM, spodosaurus wrote:
Hi guys,

I've got a problem I've not encountered before. I was given a 4-5 year
old PC to have a tinker with and the amount of dust in it was ungodly.
It had killed the video card fan, but a capacitor on the card was
already bulging and leaking so I replaced the card. Unfortunately,
there's still this hissing sound. I've stopped all the fans, even the
new graphics card one, one at a time to see if they were related -
they're not the cause. Then, while the side panel was off, I noticed
that when I scrolled with the mouse the hiss would fluctuate with each
notch on the mouse wheel! I can repeat this and it only occurs when a
window is actually scrolling, not when you just use the mouse wheel.
Does anyone have any ideas what this could be? The tops of the caps on
the mainboard all look good, and the sound is so noticeable even with
the case closed I'd imagine if it was a venting capacitor it would've
burnt out by now. I'm out of ideas! argh!

TIA,

Ari


Okay, a bit more information: the his fluctuates (starts stops rapidly)
when the computer is processing - such as installing the ATI catalyst
pack. It's not DVDROM noise, and it's not HDD noise. When checking the
properties to check files sizes on a large group of folders the hard
drive makes it's noises but the hiss barely wavers. I'm starting to
think it's a capacitor again...

Because it seems to be load sensitive, it might be an audible sub-
harmonic of the switching power supply. Power supplies are cheap.

On 6/12/2010 8:28 AM, Ngoima wrote:
On Sat, 12 Jun 2010 16:15:04 +0800, spodosaurus wrote:

On 12/06/2010 3:59 PM, spodosaurus wrote:
Hi guys,

I've got a problem I've not encountered before. I was given a 4-5 year
old PC to have a tinker with and the amount of dust in it was ungodly.
It had killed the video card fan, but a capacitor on the card was
already bulging and leaking so I replaced the card. Unfortunately,
there's still this hissing sound. I've stopped all the fans, even the
new graphics card one, one at a time to see if they were related -
they're not the cause. Then, while the side panel was off, I noticed
that when I scrolled with the mouse the hiss would fluctuate with each
notch on the mouse wheel! I can repeat this and it only occurs when a
window is actually scrolling, not when you just use the mouse wheel.
Does anyone have any ideas what this could be? The tops of the caps on
the mainboard all look good, and the sound is so noticeable even with
the case closed I'd imagine if it was a venting capacitor it would've
burnt out by now. I'm out of ideas! argh!

TIA,

Ari


Okay, a bit more information: the his fluctuates (starts stops rapidly)
when the computer is processing - such as installing the ATI catalyst
pack. It's not DVDROM noise, and it's not HDD noise. When checking the
properties to check files sizes on a large group of folders the hard
drive makes it's noises but the hiss barely wavers. I'm starting to
think it's a capacitor again...

Because it seems to be load sensitive, it might be an audible sub-
harmonic of the switching power supply. Power supplies are cheap.


Also locate an outlet tester and verify the outlet is properly grounded
and if in the USA the little slot is the hot one. Not the first time I
have found bad or defective outlets, including factory made outlet strips.

I find those little three prong outlet testers purchased at a home
center for about $7.00 are well worth the cost for testing outlets in
the USA. If the correct lights or led's come on then it's good,
anything else and it's time to fix things. Much faster than draging out
the old volt meter or those cheap two prong voltage testers.

On Jun 12, 3:59 am, spodosaurus wrote:
Hi guys,

I've got a problem I've not encountered before. I was given a 4-5 year
old PC to have a tinker with and the amount of dust in it was ungodly.
It had killed the video card fan, but a capacitor on the card was
already bulging and leaking so I replaced the card. Unfortunately,
there's still this hissing sound. I've stopped all the fans, even the
new graphics card one, one at a time to see if they were related -
they're not the cause. Then, while the side panel was off, I noticed
that when I scrolled with the mouse the hiss would fluctuate with each
notch on the mouse wheel! I can repeat this and it only occurs when a
window is actually scrolling, not when you just use the mouse wheel.
Does anyone have any ideas what this could be? The tops of the caps on
the mainboard all look good, and the sound is so noticeable even with
the case closed I'd imagine if it was a venting capacitor it would've
burnt out by now. I'm out of ideas! argh!

Quiet room and at least one good ear. Long enough piece of wood, a
dowel, to place against suspect components and the bone behind your
ear. I've also used long screwdrivers and a mechanic
stethoscopes...carefully.

On Jun 12, 10:59*am, spodosaurus wrote:
they're not the cause. Then, while the side panel was off, I noticed
that when I scrolled with the mouse the hiss would fluctuate with each
notch on the mouse wheel! I can repeat this and it only occurs when a
window is actually scrolling, not when you just use the mouse wheel.

Cool. That doesn't sound like a bug, that sounds like a feature.

I would try and understand the mechanism behind this and then patent
it. You never know...

RL

On 12/06/2010 9:28 PM, Ngoima wrote:
On Sat, 12 Jun 2010 16:15:04 +0800, spodosaurus wrote:

On 12/06/2010 3:59 PM, spodosaurus wrote:
Hi guys,

I've got a problem I've not encountered before. I was given a 4-5 year
old PC to have a tinker with and the amount of dust in it was ungodly.
It had killed the video card fan, but a capacitor on the card was
already bulging and leaking so I replaced the card. Unfortunately,
there's still this hissing sound. I've stopped all the fans, even the
new graphics card one, one at a time to see if they were related -
they're not the cause. Then, while the side panel was off, I noticed
that when I scrolled with the mouse the hiss would fluctuate with each
notch on the mouse wheel! I can repeat this and it only occurs when a
window is actually scrolling, not when you just use the mouse wheel.
Does anyone have any ideas what this could be? The tops of the caps on
the mainboard all look good, and the sound is so noticeable even with
the case closed I'd imagine if it was a venting capacitor it would've
burnt out by now. I'm out of ideas! argh!

TIA,

Ari


Okay, a bit more information: the his fluctuates (starts stops rapidly)
when the computer is processing - such as installing the ATI catalyst
pack. It's not DVDROM noise, and it's not HDD noise. When checking the
properties to check files sizes on a large group of folders the hard
drive makes it's noises but the hiss barely wavers. I'm starting to
think it's a capacitor again...

Because it seems to be load sensitive, it might be an audible sub-
harmonic of the switching power supply. Power supplies are cheap.


Indeed, and this one was really crap. Swapped it out for a thermaltake I
had spare and all is very well now

--
spammage trappage: remove the underscores to reply
Many people around the world are waiting for a marrow transplant. Please
volunteer to be a marrow donor and literally save someone's life:
http://www.abmdr.org.au/
http://www.marrow.org/

In article ,
spodosaurus writes

the his fluctuates (starts stops rapidly)
when the computer is processing - such as installing the ATI catalyst
pack. It's not DVDROM noise, and it's not HDD noise. When checking the
properties to check files sizes on a large group of folders the hard
drive makes it's noises but the hiss barely wavers. I'm starting to
think it's a capacitor again...

I agree. It'll be either the caps on the CPU voltage regulator
circuitry, or the output caps in the power supply, or both.

If you have a spare known good PSU you can use to test, try that first.

--
Mike Tomlinson