OT - Degauss Monitors

  • Thread starter Thread starter Kim
  • Start date Start date
K

Kim

I realize this has nothing to do with Windows, but was
hoping someone might have an idea. I have several
monitors in my building that the display 'waves' on. It's
making the users seasick! If there is an internal
automatic degausser in these monitors, it is not working.
Does anyone know of an external device that will help with
this situation.

TIA
Kim
 
It is not a degauss issue you are getting some kind of RF interference or
the refresh rate needs to be adjusted. Try setting the refresh rate higher
in control panel -> display properties. Look for clock radios and other
electronic devices, also make sure nothing like microwaves and refrigerators
plugged into the same power circuit.
 
Kim said:
I realize this has nothing to do with Windows, but was
hoping someone might have an idea. I have several
monitors in my building that the display 'waves' on. It's
making the users seasick! If there is an internal
automatic degausser in these monitors, it is not working.
Does anyone know of an external device that will help with
this situation.

TIA
Kim
Click to expand...

the internal degauser is the thing that makes crt monitors go 'thunk' when
you turn them on. it quickly turns itself off and doesn't do anything until
the next time the monitor is turned on. the purpose is to remove any
residual magnetism, not provide any continuous protection. you can get
external degausers, but they are meant for the same thing. if a monitor is
continuously 'waving' then it is probably too near to some other device that
is generating a magnetic field at 50/60hz. move the monitor away from
ups's, some old flourescent lamps, and any other electrical equipment to see
if it stops. the fields could also come from high current conductors in
walls, ceilings or floors in a large building, or in rare cases from power
lines outside the building... if it isn't something easy sitting around the
monitor get your environmental monitoring office to bring in a magnetic
field meter to find the source and figure out how to fix the problem.
 
I'd be very leery of using an external degausser these days. I know
some televisions use (or used to use) a metal mask to provide separation
of the color pixel groups and that using the external degausser would
warp this mask and permanently damage the television. Can't recall
seeing a computer monitor with a metal mask but that doesn't mean there
aren't any (or someone trying to use a television on the video out of a
video card).

Degaussing helps with residual magnetic fields. The artifact would
probably be a colored area on the screen, say a greenish corner area.
The magnetism is deflecting the electrons enough to misalign them as to
which pixel they hit. If you use an external degausser, start with the
monitor on and displaying a colored test pattern that changes through
repeated screens (so you know what to expect) and start with the
degausser positioned far away. Turn the degausser so it is sideways to
the monitor's screen (for minimal effect), tilt, and wave around until
you start seeing the effect on the monitor screen but don't get too
close. Pull the degausser away and tilt again so it is sideways, keep
moving away, and then turn off. Try deguassing very little at first to
see if the effect to clear the artifact remains permanent. The
degaussers built into a monitor are nowhere as strong as those for
external units.

Obviously you need to degauss the monitor far away from other magnetic
sensitive devices, like drives, floppies, tapes, etc. Else you could
"degauss" (erase or damage) more than just the monitor.

I'd rather try using the monitor's deguass circuit than an external
unit. If your monitor has a degauss button (and often they cannot be
reused until 5 minutes have elapsed to thermally protected the load on
the circuit), just power it off and on many times. I remember once
having to do it something like 20 times to get rid of a tinted area in a
corner. If that doesn't work, I'd rather take it to a tube shop to have
them do it so it they damage it then they replace it (make sure they
don't disqualify their liability for degaussing a monitor). I just
don't trust my expertise with an external degauss coil.
 
CRT's use a mask and provide for their own degaussing. LCD or LED flat
panels don't have a mask.
 
in news:[email protected]:
CRT's use a mask and provide for their own degaussing. LCD or LED flat
panels don't have a mask.
Click to expand...

LCD or LED flat panels don't exhibit gauss artifacts since they don't
shoot electrons susceptible and controlled by magnetism to aim at and
energize phosphor dots on a screen, so they don't need degaussing. Kim
wouldn't be asking about degaussing for an LED or LCD display. How is a
residual magnetic field, unshielded speakers, magnets, or degaussing
coils going to affect a non-magnetically controlled display device?
There's a reason why you don't hear a degaussing "thunk" in non-CRT
displays: there's nothing that can be degaussed because there's nothing
that is magnetically controlled or suspectible.

I guess I never considered that someone would think of using a
degaussing coil on their LED alarm clock or LCD watch. But then you get
the idiot that sues Sears because he bought a lawn mower to lift up and
trim his hedges simply because the manual didn't say the mower couldn't
be used for that purpose. Hey, I'm sure the lawn mower manual also
doesn't mention that it cannot be used to do haircuts. Too bad he
didn't chop off his head to become the proud but dead recipient of a
Darwin Award (http://www.darwinawards.com/).
 
The point I was making is that IF there is a need to degauss then the
monitor provides the circuitry. And it can be done with the push of a
button.
 
I've seen monitors so badly messed up from kids putting very strong
magnets on them (maliciously, of course) that the internal degaussing
ckt has no effect whatsoever. At that point it becomes a choice between
trying an external degaussing coil or replacing the monitor.

Steve
 
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