Shutdown Noise?

[RustyGates]

At shutdown, I always get a loud noise from the speakers, it sounds like
the tearing of cloth. It occurs a split second before power goes off during
the black screen, and seems to be after all progs are shut down but I'm not
sure about that.

It occurs even with my AC97 chip deactivated in BIOS! It occurs even
after a reformat and fresh install of XP. It seems like an electrical
discharge through the speakers, and I'm stumped. Mute the speakers
and the noise occurs; unplug the speakers and there is no noise. TIA

[XP Pro, SP1, current on updates, 8KNXP mobo, SATA HDs. I built
the system about a year ago, never experience this until a couple of
months ago]

RustyGates (no, I'm not in his will)

 

[CS]

At shutdown, I always get a loud noise from the speakers, it sounds like
the tearing of cloth. It occurs a split second before power goes off during
the black screen, and seems to be after all progs are shut down but I'm not
sure about that.

It occurs even with my AC97 chip deactivated in BIOS! It occurs even
after a reformat and fresh install of XP. It seems like an electrical
discharge through the speakers, and I'm stumped. Mute the speakers
and the noise occurs; unplug the speakers and there is no noise. TIA

[XP Pro, SP1, current on updates, 8KNXP mobo, SATA HDs. I built
the system about a year ago, never experience this until a couple of
months ago]

RustyGates (no, I'm not in his will)

Hi Rusty:

It may be a bad power supply that's causing the noise when it shuts
down. (defective filtering) I ran across that problem on occasion
when I repaired stereo equipment.

You might want to try a replacement power supply. It's possible the
one you originally had when you built the computer has developed
problems. New power supplies are not expensive but require some time
to change out. Good luck.

 

[Bee]

RustyGateswrote:

At shutdown, I always get a loud noise from the speakers...

When a TV (the good, old CRT kind) is turned off, there is a short
though soft crunching noise. It can be detected if one is sufficiently
close to the set. Would you say this noise is a close approximation of
the noise from your PC at the point of power cut-off ? Or, is this
noise from the PC much louder?

Bee.

 

[RustyGates]

It's a very loud noise, can be heard throughout the house; it lasts a good
second or two...and the pitch drops from start to the end.

Could very well be the power supply...something is discharging thru
the speakers, even with the sound card turned off or muted. It may
not be software related because I've fiddled with msconfig and can't
learn a thing by selective shutdown of my programs.

 

[Bee]

It's a very loud noise, can be heard throughout the house; it lasts a good
second or two...and the pitch drops from start to the end.
Could very well be the power supply...something is discharging thru
the speakers, even with the sound card turned off or muted...

A loud noise in decrescendo extinguishing in "a good second or two"
certainly suggests a "discharge thru the speakers". It is consistent
with the CS's theory of a defective PSU (collapse of an electromagnetic
field and/or the decay of a capacitor charge). You might like to seek
further opinion from the hardware NG:
news://msnews.microsoft.com/microsoft.public.windowsxp.hardware
Good luck.

Bee.

 

[RustyGates]

Thanks Bee, this will be my last post. I disconnected a 120mm
case fan and that seems to have stopped the noise.

It's a very loud noise, can be heard throughout the house; it lasts a good
second or two...and the pitch drops from start to the end.
Could very well be the power supply...something is discharging thru
the speakers, even with the sound card turned off or muted...

A loud noise in decrescendo extinguishing in "a good second or two"
certainly suggests a "discharge thru the speakers". It is consistent
with the CS's theory of a defective PSU (collapse of an electromagnetic
field and/or the decay of a capacitor charge). You might like to seek
further opinion from the hardware NG:
news://msnews.microsoft.com/microsoft.public.windowsxp.hardware
Good luck.

Bee.