Monitor Squeal

[Murphy]

When I start Slackware the screen squeals and continues to do so until I
start gnome and change the screen resolution from 1024X768 to 800X600

The monitor is a 17" and should handle 1024X768

How can I get it to work without the piercing squeal ?

[Minderbinder]

Post by Murphy
When I start Slackware the screen squeals and continues to do so until I
start gnome and change the screen resolution from 1024X768 to 800X600
The monitor is a 17" and should handle 1024X768
How can I get it to work without the piercing squeal ?

Have you set your Vsync and Hsync ranges correctly? You might be trying to
use a refresh rate outside the supported range. Alternatively, you may
just have hit on a particularly noisy resolution/refresh rate combination.
For example, my monitor gives funny distortion above 75Hz at 1280x1024,
but has no problem with higher resolutions and rates. Try setting a
different refresh rate (say, 70 or 75Hz).

Cheers,
Minderbinder.

[Murphy]

Post by Minderbinder

Post by Murphy
When I start Slackware the screen squeals and continues to do so until I
start gnome and change the screen resolution from 1024X768 to 800X600
The monitor is a 17" and should handle 1024X768
How can I get it to work without the piercing squeal ?

Have you set your Vsync and Hsync ranges correctly? You might be trying to
use a refresh rate outside the supported range. Alternatively, you may
just have hit on a particularly noisy resolution/refresh rate combination.
For example, my monitor gives funny distortion above 75Hz at 1280x1024,
but has no problem with higher resolutions and rates. Try setting a
different refresh rate (say, 70 or 75Hz).
Cheers,
Minderbinder.

My current LILO & KDE config is 1024X768 61Hz which produces a squeal...
My current Win2K config is 1024X768 75Hz which does not squeal and if I
change the Windows config to 60Hz the monitor starts to squeal...

So the million dollar question is how do I specify a refresh rate of 75Hz in
Linux ? It's not listed as an option in lilo.conf not is it listed in KDE
under "Screen Resize and Rotate"
.

[Minderbinder]

Post by Murphy

Post by Minderbinder

Post by Murphy
When I start Slackware the screen squeals and continues to do so until
I start gnome and change the screen resolution from 1024X768 to 800X600
The monitor is a 17" and should handle 1024X768
How can I get it to work without the piercing squeal ?

Have you set your Vsync and Hsync ranges correctly? You might be trying
to use a refresh rate outside the supported range. Alternatively, you
may just have hit on a particularly noisy resolution/refresh rate
combination. For example, my monitor gives funny distortion above 75Hz
at 1280x1024, but has no problem with higher resolutions and rates. Try
setting a different refresh rate (say, 70 or 75Hz).
Cheers,
Minderbinder.

My current LILO & KDE config is 1024X768 61Hz which produces a squeal...
My current Win2K config is 1024X768 75Hz which does not squeal and if I
change the Windows config to 60Hz the monitor starts to squeal...
So the million dollar question is how do I specify a refresh rate of 75Hz
in Linux ? It's not listed as an option in lilo.conf not is it listed in
KDE under "Screen Resize and Rotate"
.

If you specify the correct vertical and horizontal refresh ranges in
XF86Config (or xorg.conf), usually X will select the highest supported
refresh rate for any resolution. You can see the ranges (HorizSync,
VertRefresh) for my monitor in the Monitor section of my config file
(/etc/X11/xorg.conf). Note that I've also got a custom modeline that drops
my monitor's refresh rate to 75Hz when at resolution 1280x1024. You can't
just copy the numbers from my config, of course. You need to find the
correct ranges from your manual or manufacturer's specs.

Section "Monitor"
Identifier "Monitor0"
VendorName "Hitachi"
ModelName "CM721F"
DisplaySize 360 270
HorizSync 31.0 - 95.0
VertRefresh 50.0 - 120.0
Modeline "***@75" 138.54 1280 1368 1504 1728 1024 1025 1028 106
9 -HSync +Vsync
Option "DPMS"
EndSection

[7]

Post by Murphy
When I start Slackware the screen squeals and continues to do so until I
start gnome and change the screen resolution from 1024X768 to 800X600
The monitor is a 17" and should handle 1024X768
How can I get it to work without the piercing squeal ?

You can try changing settings with xvidtune.
Sometimes the problem is transformer broken or small
particles have loosened inside, and the squeel becomes
impossible to remove as it resonates with the high
frequencies at which the HT transformer is working.
Not a good sign actually if its a big noise.

[Morningdew]

Post by 7

Post by Murphy
When I start Slackware the screen squeals and continues to do so until I
start gnome and change the screen resolution from 1024X768 to 800X600
The monitor is a 17" and should handle 1024X768
How can I get it to work without the piercing squeal ?

You can try changing settings with xvidtune.
Sometimes the problem is transformer broken or small
particles have loosened inside, and the squeel becomes
impossible to remove as it resonates with the high
frequencies at which the HT transformer is working.
Not a good sign actually if its a big noise.

hmmm.... never heard that one. I have heard solid state electronics
squeal, such as capacitors. Some people can't even hear the squeals...
women seem to be better at hearing the high frequencies. I hear them,
though maybe I just am more sensitive to high freq than most men. Not
exaclty a blessing... I have a harder time with conversations where
there is a lot of background noise. I can remember back when my dad had
a computer shop in the 80's. I would mention some of the monitors made
noises but most the other guys didn't hear it, though the girls almost
all did.

morningdew.

[E. Charters]

The solution is to get a rhesus monkey as a pet, as they are
very sensitive to high frequency noises. You will probably notice
that the monitor begins to squeal after it has been on for some
time. The monkey will notice this earlier and begin to get agitated
and throw feces at you, while shrieking loudly. This is a sign that
you should throw the monkey a banana, and turn off the monitor for
half an hour. After the tube has cooled down to 75 degrees C you can
start up again. Perhaps aiming a large 120 V fan towards the back of the
monitor might alleviate the condition.

Another idea, although it is unlikely to solve the problem is to go
into xf86config and reset the horizontal synch frequencies of the
monitor to a lower value, while making sure you have the right card
driver. Try the SVGA driver out for noise too. If you fool with screen
resolutions in X, cutting back the higher res screens, it may make a
difference. You can do that easiest in XF86Setup, if you have that
Tcl/tk program. It is available at the Slackware home page.
http://www.slackware.com

xvidtune can be dangerous. I would rather fool with the horizontal
synchs than fool with xvidtune. It can give bizarre and unstable
results. I have burnt out fixed frequency monitors in X by setting the
synchs wrong, but if you read the docs and act conservatively, it should
be no never mind.

EC<:-}

Post by Morningdew

Post by 7

Post by Murphy
When I start Slackware the screen squeals and continues to do so until I
start gnome and change the screen resolution from 1024X768 to 800X600
The monitor is a 17" and should handle 1024X768
How can I get it to work without the piercing squeal ?

You can try changing settings with xvidtune.
Sometimes the problem is transformer broken or small
particles have loosened inside, and the squeel becomes
impossible to remove as it resonates with the high
frequencies at which the HT transformer is working.
Not a good sign actually if its a big noise.

hmmm.... never heard that one. I have heard solid state electronics
squeal, such as capacitors. Some people can't even hear the squeals...
women seem to be better at hearing the high frequencies. I hear them,
though maybe I just am more sensitive to high freq than most men. Not
exaclty a blessing... I have a harder time with conversations where
there is a lot of background noise. I can remember back when my dad had
a computer shop in the 80's. I would mention some of the monitors made
noises but most the other guys didn't hear it, though the girls almost
all did.
morningdew.