Electrical noise from power supply

[Anthony]

This is more of an EE question than a computer hardware question, but
I thought someone else here might have run into this:

I recently installed a geForce4 64MB PCI video card into my Shuttle
SV25 mini-system. This allowed me to do some things that the onboard
video did not; for example, there are some pretty nice high-framerate
3D screensavers that came with the Linux disto that I have installed,
and those were "grayed out" before I installed this card.

Anyway, when I'm running a high-framerate 3D app like one of those
screensavers, the power supply emits a nasty "screechy" electrical
noise. It's not the power supply fan -- it's a component (probably a
transformer) inside the power supply.

Now I know from semi-similar experience with CRTs that I can open the
power supply up and push a little on that transformer, and
reduce/eliminate the noise that way. But that isn't exactly an ideal
solution. Has anyone here run into a problem like this? Any (better)
ideas on how to fix it?

Thanks,
Anthony
http://nodivisions.com/

 

[Cyrus]

Replace your 200W Power Supply with 300W or 350W then everything will be
fine.

Cyrus

 

[Steve Reinis]

Yes, you can silence the component that is complaining about the load, but
it will most likely die in a short time. You are stressing something by
pulling too much current from the power supply and it won't happily go on
for too long... Usually filter caps will whine and screech...then POOF,
smoke and lots of white fluffy goop in your PSU.

I had an older 145 watt PSU that I loved because the fan was a variable
speed fan with a lead I could attach to the motherboard for fan control.
When I put the system to sleep, not only would case fans and processor fan
shut off, the fan in the PSU would shut off as well. This made for a
totally silent system when it was asleep. However, once I started using
that PSU to run a PIII based motherboard with two 7200 RPM hard drives, a
CDRW drive, a DVD drive, a GeForce 64MB AGP video card, video capture card,
modem, NIC, sound card, SCSI/Scanner card, and multiple USB devices... It
wasn't able to handle the load and it quickly died.

You may wish to invest in a better PSU.

-Steve

 

[kony]

This is more of an EE question than a computer hardware question, but
I thought someone else here might have run into this:

I recently installed a geForce4 64MB PCI video card into my Shuttle
SV25 mini-system. This allowed me to do some things that the onboard
video did not; for example, there are some pretty nice high-framerate
3D screensavers that came with the Linux disto that I have installed,
and those were "grayed out" before I installed this card.

Anyway, when I'm running a high-framerate 3D app like one of those
screensavers, the power supply emits a nasty "screechy" electrical
noise. It's not the power supply fan -- it's a component (probably a
transformer) inside the power supply.

Now I know from semi-similar experience with CRTs that I can open the
power supply up and push a little on that transformer, and
reduce/eliminate the noise that way. But that isn't exactly an ideal
solution. Has anyone here run into a problem like this? Any (better)
ideas on how to fix it?

Thanks,
Anthony
http://nodivisions.com/

If it's the primary transformer there isn't a whole lot you can do
with a _reasonable_ amount of work... taking out the transformer and
unwinding it, or at least unwrapping it and coating it so it's
non-resonant, isn't feasible.

There is one possible easy fix, to put a (entirely plastic) wire-tie
around the transformer, or multiple ties, as many as seems necessary,
but due to the shape you might need get it really tight to do any
good. Then there's the possibility of using super-glue, dripped down
into it, though I"m not sure that the enamel coating on the wires is
impervious to super-glue (you might want to check on that before
trying it).


Dave