monitor problems

Has anyone experienced this fault on a CRT monitor - a 4 yr old LG
Studioworks.

Once or twice a session the display momentarily has a fit! The image dulls,
appears to zoom out of the screen and then contracts back to normal size and
brightness. This happens in a split second and there is also a 'crackle'.
It started happening once every several hours but the freqency is
increasing.

If this is a known but cheaply fixed fault fine. Otherwise I'm loathe to lay
out $X only to be told that it'll cost $Y to fix which might be a good part
of the cost of a new monitor.

F

Paul
Fri Apr 25 05:38:27 PDT 2008

frog wrote:
> Has anyone experienced this fault on a CRT monitor - a 4 yr old LG
> Studioworks.
>
> Once or twice a session the display momentarily has a fit! The image dulls,
> appears to zoom out of the screen and then contracts back to normal size and
> brightness. This happens in a split second and there is also a 'crackle'.
> It started happening once every several hours but the freqency is
> increasing.
>
> If this is a known but cheaply fixed fault fine. Otherwise I'm loathe to lay
> out $X only to be told that it'll cost $Y to fix which might be a good part
> of the cost of a new monitor.
>
> F
>

The sound could be related to high voltage arcing inside the monitor.

When it happened to my CRT, a temporary solution was to reduce the
resolution and refresh rate. There is some relationship between
resolution and refresh rate, and the voltage level on the high voltage
wiring and circuits.

For example, if you are at 1280x1024 at 85Hz, try 1024x768 at 60Hz. Then
see if the monitor arcs.

In my case, there seemed to be arcing over the surface of the flyback
transformer. With some materials, a "carbon track" will develop, and
that forms a conducting path which is hard to correct. If a component
has burn marks or pin holes in some insulation, then perhaps it should
be replaced. There are also materials that can be used to apply external
insulation in a high voltage circuit, but using them is useless if
the surface of the component is already compromised (burned).

A TV repair shop may be able to look at it for you, and give you some
idea which component needs to be replaced. If I thought I'd be able to
get replacements parts (a new flyback), I might have had mine fixed.
I just retired it instead, and switched to an LCD (which is not as nice
in some respects). Doing so, means I went from wasting 200W power in
the CRT, to less than 36W for the 17" LCD.

There are other failure mechanisms that can lead to the arcing sound.
For example, a CRT design may have circuit features, to prevent the
tube voltage from going too high. If the voltage becomes high
enough, the tube can emit x-rays, so safety features are added
to protect against that kind of failure (too high a voltage). Not all
arcing sounds are caused by surface arcing on high voltage components,
but may be caused by a safety feature.

Paul

Bob
Fri Apr 25 08:12:53 PDT 2008

The monitor is on it's way to the recycle center, inventory you wallet
as you will need to replace it.

frog wrote:

> Has anyone experienced this fault on a CRT monitor - a 4 yr old LG
> Studioworks.
>
> Once or twice a session the display momentarily has a fit! The image dulls,
> appears to zoom out of the screen and then contracts back to normal size and
> brightness. This happens in a split second and there is also a 'crackle'.
> It started happening once every several hours but the freqency is
> increasing.
>
> If this is a known but cheaply fixed fault fine. Otherwise I'm loathe to lay
> out $X only to be told that it'll cost $Y to fix which might be a good part
> of the cost of a new monitor.
>
> F
>
>

Farad'n
Fri Apr 25 16:31:01 PDT 2008

On Fri, 25 Apr 2008 20:45:31 +1000, "frog" <frog@bigpond.net.au>
wrote:

>Has anyone experienced this fault on a CRT monitor - a 4 yr old LG
>Studioworks.
>
>Once or twice a session the display momentarily has a fit! The image dulls,
>appears to zoom out of the screen and then contracts back to normal size and
>brightness. This happens in a split second and there is also a 'crackle'.
>It started happening once every several hours but the freqency is
>increasing.
>
>If this is a known but cheaply fixed fault fine. Otherwise I'm loathe to lay
>out $X only to be told that it'll cost $Y to fix which might be a good part
>of the cost of a new monitor.
>
>F
>
This is a purely hardware question that has NO relation to the XP OS,
hence it is out of place HERE.

Ask elsewhere

frog
Sat Apr 26 17:38:00 PDT 2008

Malke,
I'm trying to get hold of a 2nd computer - on loan or permanently - when
I'll be able to do as you suggest. The graphics card is a couple of years
old so hopefully it isn't that.

Paul,
"Retirement" is the most likely prognosis so far.

Thanks for your helpful comments guys. I'll be starting to look at a
suitable replacement now, beginning with a decision on the CRT v LCD for
graphics work controversy, which, Farad'n, I'll be with other newsgroups;
but not, I hasten to add, in compliance with your inane and censorious
comments. Refer to the title of this newsgroup. I note you seem to waste
your life scattering the same message across many posts which seems to
constitute the sum total of your assistance to people seeing help.

M
Wed Apr 30 08:00:53 PDT 2008


"frog" <frog@bigpond.net.au> wrote in message
news:%23ps7FGspIHA.4912@TK2MSFTNGP03.phx.gbl...
> Has anyone experienced this fault on a CRT monitor - a 4 yr old LG
> Studioworks.
>
> Once or twice a session the display momentarily has a fit! The image
> dulls, appears to zoom out of the screen and then contracts back to normal
> size and brightness. This happens in a split second and there is also a
> 'crackle'. It started happening once every several hours but the freqency
> is increasing.
>
> If this is a known but cheaply fixed fault fine. Otherwise I'm loathe to
> lay out $X only to be told that it'll cost $Y to fix which might be a good
> part of the cost of a new monitor.
>

The high voltage circuit (known technically as the EHT) has a fault. The
crackle is arcing either within the EHT generator, in the cable carrying the
high voltage to the tube's final anode and PDA, or in the tube connector
itself. It could just be in the tube, but this is unlikely. When the arc
occurs, the EHT voltage drops and the expanding picture is the classic
symptom of depressed EHT. The chances are that it is repairable and any
competant TV repairer should have little difficulty.

However, as you have already surmised, it is worth bearing in mind that LCD
monitors are cheap enough these days that they are not going to be
significantly more expensive than what a TV repairer will charge you.