LCD monitor weird pixel distortion/noise, see pictures!

  • Thread starter Thread starter Simon Simonsen
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Simon Simonsen

Hi!

My father have had an NEC Multisync LCD1970GX for a year or so.
At first the monitor seemed fantastic; crisp picture, beautiful
reflective surface and brilliant colours.
But then came summer.

When viewing pictures or playing games, just intense or diverse
graphics on the screen, the monitor displays hundreds of flickering
pixels that don't fit in with the image (pixelfubars). They seem to
follow certain contours sometimes and at least will appear in certain
places in certain pictures.
If I view a picture in Picasa and use the "fill light" control to raise
the brightness of the picture, the pixelfubars will shift on screen,
disappear or appear. Ie they seem to appear for a specific brightness
value of a pixel and perhaps for specific colours, hard to tell.

You can see some pictures taken with a digicam on my flickr account:
http://flickr.com/photos/simonss/sets/72157594191125002/

The pixelfubars should be obvious. Some of these flicker from one pixel
to neighbour pixel, a certain uncertainty ;)

The monitor is connected to the graphics card with an analogue cable,
though I could buy a DVI cable for both connection points. I first want
to understand what the hell this is :)

OOooh yess.. IMPORTANT NOTICE: I mentioned summer... yes the effect
actually disappear during winter, or colder temperatures. I am
convinced the effect is heat induced because it has appeared only two
times and only when the avarage temp is high (~25 C?)
 
This is something you will not be able to fix yourself. If your monitor
is under warranty, it should be sent back for exchange or service ASAP.


I have serviced LCD monitors with similiar problems. Most of the time,
it was a number of capacitors in the processing board, and in the power
supply sections that were going high in their ESR values.

As electronic components age, they can become thermo sensitive before
they fail. As time goes on, they will get worse when they start to have
problems.

We use a scope, pattern test generator, DVM, LCR analyser, and ESR
meter to determine the areas of the faults, to zero in on the caps.

The parts used in your monitor are mostly all surface mount high
density components. They are difficult to change using conventional
soldering tools. You will require the proper tools, skills, service
manuals, and training to work inside of your monitor.

As for the generic type of components, once the defective ones have
been located, most any experienced service tech who is properly
equiped, can change them. If there are any propriotory components such
as custom IC's, or devices that have to be changed, NEC will not sell
them directly to non authorised servicers.

Your best bet, is to call NEC, or one of their authorised service
centers to have your monitor serviced. Most of the time, the authorised
service center will service the monitor at the modular level, unless
the fault is a simple one.

If your monitor is not an expensive high end model, you would be best
off getting a new one. The prices of the regular consumer monitors have
dropped considerably, and their quality has far improved.

The life expency of most of these monitors is about 30,000 hours
average. Some will last a little longer. Some manufactures specify up
to 60,000 hours. We have never seen one last that long.


Jerry G.
======
 
Hi!

My father have had an NEC Multisync LCD1970GX for a year or so.
At first the monitor seemed fantastic; crisp picture, beautiful
reflective surface and brilliant colours.
But then came summer.

When viewing pictures or playing games, just intense or diverse
graphics on the screen, the monitor displays hundreds of flickering
pixels that don't fit in with the image (pixelfubars). They seem to
follow certain contours sometimes and at least will appear in certain
places in certain pictures.
If I view a picture in Picasa and use the "fill light" control to raise
the brightness of the picture, the pixelfubars will shift on screen,
disappear or appear. Ie they seem to appear for a specific brightness
value of a pixel and perhaps for specific colours, hard to tell.

You can see some pictures taken with a digicam on my flickr account:
http://flickr.com/photos/simonss/sets/72157594191125002/

The pixelfubars should be obvious. Some of these flicker from one pixel
to neighbour pixel, a certain uncertainty ;)

The monitor is connected to the graphics card with an analogue cable,
though I could buy a DVI cable for both connection points. I first want
to understand what the hell this is :)

OOooh yess.. IMPORTANT NOTICE: I mentioned summer... yes the effect
actually disappear during winter, or colder temperatures. I am
convinced the effect is heat induced because it has appeared only two
times and only when the avarage temp is high (~25 C?)
Click to expand...


Point a desk fan at the bottom rear of the monitor to push
more cool air up through it. If it helps that would tend to
indicate overheating or at least heat-induced problems.

How hot is the room? Is the monitor enclosed or in a tight
area behind it so there isn't much passive airflow?

Regardless, determine what the warranty period is. Some
might have a shorter interval of on-site service or even a
short warranty, it could be useful to know if any kind of
warranty coverage changes at the one year mark so you don't
lose that opportunity... since even if a fan helps, you
shouldn't have to do it unless you are operating the unit in
temps above it's spec'd tolerable environment. Perhaps the
back of the manual details this or you could ask them, but
IMO you are looking at replacing it under warrant if
possible.
 
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