I´m asking you for any help about a problem affecting both my NEC SpectraView 2490 and my NEC MultiSync 2490WUXi² LCD monitors.
Description of the problem:
After a year - year and a half of use, both displays began to show irregularly shaped dark "shadows" on the right edge from top to bottom of the screen. At first they are not much annoying because they don't affect the main working area, so I tend not to care much about it; also somewhat reassured as I can see that they change over time and don't seem to be a permanent electronic nor mechanical problem (and maybe hoping they will disappear as they have appeared)
In the next year they have evolved slowly, but lately the change pace has increased, and they are getting wider and "moved" towards the center of the screen affecting the main working area and leaving the displays marginally useful for my professional image editing work.
Other characteristics of the issue are:
- As said, the problem seems to be the same, affecting the same area of the screen and appearing between an interval of few months in both monitors (first the LCD2490WUXi2, who seem to ever "lead" in the process, then the SpectraView 2490).
- The "shadows" are near invisible at the moment of turning on the sets, with a very subtle opposite effect: a clear (light not dark) "cloud" (barely noticeable against the blue uniform background of the start up of the system) the same shape as the "shadows" that appear after 10-15 mins of warm-up, and stay so mostly unchanged for the rest of each session.
- The "shadows" change slowly over time, "moving" towards the center of the screen as a wave in a beach, with different relative "speed" of the "leading edge", diffusing themselves and leaving relatively clear areas previously covered by them.
In the attached images you can see the problem in photos taken one and a half month ago, and the evolution to their present state.
Other info maybe relevant:
- Both have been bought on Nov 2009 and have now roughly 23.000 hrs of operation. The problem began to show at 9.000-10.000 hrs.
- They are connected to the same Mac Pro workstation and placed side by side, sharing the same working conditions.
- They have ever operated following the recommendations in the User Manual, specifically the ones about environment conditions of temperature and moist, cleaning, low brightness level settings, periodic calibration, exposure to sunlight or magnetic fields, etc
- It seems no other part or subsystem of them have any type of malfunction (abnormal heating, noise, defects in pixels, deformation of images nor colors, etc)
- The "shadows" seems to be not affected by short time pressure or temperature change applied to the front of the panel (I tried to gently press with my finger and apply some cold directly over them with no results)
- Off course they are not dirt in the surface of the panel as I tried to remove them by carefully cleaning the displays in many occasions.
My guess
As I said, due to the wavy shape, "evolving" nature of the "shadows" and lack of other problems with the sets, I doubt it's a electric-electronic issue (bad PCBs, ICs, caps, connectors, power, etc) or mechanical issue (excessive press in screws, edges or in the middle of display, cracks, bends, etc).
It is a form of non-uniform brightness issue, seemingly produced by local interference with the backlight. But due to... what?
So I searched a little on the web and found some references to a weird "mura" effect that (at least apparently) resembles my problem. More or less it can be checked in the webpages:
http://www.avsforum.com/t/1467644/lc...nce-what-to-do
http://www.behardware.com/articles/5...ad-pixels.html
Based on the above, It seems to me that it can be:
- Very thin dirt between the different back layers of the panel (the least probable to me)
- Some form of ionization of the LCD TFT panel (following what the Beharware site says about the "type II mura" they describe). Intriguing, but too technical for me.
- Thermic induced deformation of the diffuser or polarizing layers or their in-between interface (glue?), causing refractive interlayer problems or semi transparency due to slight changes in polarization orientation (most probable to me)
So, please, help me with
- Anyone knows that problem?. Which is their nature and the cause of it?
- There are any solution or improvement possible? Which ones exactly?
- Can myself perform any action to alleviate or fix the issue?
- It's a problem plaguing the whole LCD technology, the NEC brand, or just I have had bad luck with my monitors?
Thank you very much in advance
Description of the problem:
After a year - year and a half of use, both displays began to show irregularly shaped dark "shadows" on the right edge from top to bottom of the screen. At first they are not much annoying because they don't affect the main working area, so I tend not to care much about it; also somewhat reassured as I can see that they change over time and don't seem to be a permanent electronic nor mechanical problem (and maybe hoping they will disappear as they have appeared)
In the next year they have evolved slowly, but lately the change pace has increased, and they are getting wider and "moved" towards the center of the screen affecting the main working area and leaving the displays marginally useful for my professional image editing work.
Other characteristics of the issue are:
- As said, the problem seems to be the same, affecting the same area of the screen and appearing between an interval of few months in both monitors (first the LCD2490WUXi2, who seem to ever "lead" in the process, then the SpectraView 2490).
- The "shadows" are near invisible at the moment of turning on the sets, with a very subtle opposite effect: a clear (light not dark) "cloud" (barely noticeable against the blue uniform background of the start up of the system) the same shape as the "shadows" that appear after 10-15 mins of warm-up, and stay so mostly unchanged for the rest of each session.
- The "shadows" change slowly over time, "moving" towards the center of the screen as a wave in a beach, with different relative "speed" of the "leading edge", diffusing themselves and leaving relatively clear areas previously covered by them.
In the attached images you can see the problem in photos taken one and a half month ago, and the evolution to their present state.
Other info maybe relevant:
- Both have been bought on Nov 2009 and have now roughly 23.000 hrs of operation. The problem began to show at 9.000-10.000 hrs.
- They are connected to the same Mac Pro workstation and placed side by side, sharing the same working conditions.
- They have ever operated following the recommendations in the User Manual, specifically the ones about environment conditions of temperature and moist, cleaning, low brightness level settings, periodic calibration, exposure to sunlight or magnetic fields, etc
- It seems no other part or subsystem of them have any type of malfunction (abnormal heating, noise, defects in pixels, deformation of images nor colors, etc)
- The "shadows" seems to be not affected by short time pressure or temperature change applied to the front of the panel (I tried to gently press with my finger and apply some cold directly over them with no results)
- Off course they are not dirt in the surface of the panel as I tried to remove them by carefully cleaning the displays in many occasions.
My guess
As I said, due to the wavy shape, "evolving" nature of the "shadows" and lack of other problems with the sets, I doubt it's a electric-electronic issue (bad PCBs, ICs, caps, connectors, power, etc) or mechanical issue (excessive press in screws, edges or in the middle of display, cracks, bends, etc).
It is a form of non-uniform brightness issue, seemingly produced by local interference with the backlight. But due to... what?
So I searched a little on the web and found some references to a weird "mura" effect that (at least apparently) resembles my problem. More or less it can be checked in the webpages:
http://www.avsforum.com/t/1467644/lc...nce-what-to-do
http://www.behardware.com/articles/5...ad-pixels.html
Based on the above, It seems to me that it can be:
- Very thin dirt between the different back layers of the panel (the least probable to me)
- Some form of ionization of the LCD TFT panel (following what the Beharware site says about the "type II mura" they describe). Intriguing, but too technical for me.
- Thermic induced deformation of the diffuser or polarizing layers or their in-between interface (glue?), causing refractive interlayer problems or semi transparency due to slight changes in polarization orientation (most probable to me)
So, please, help me with
- Anyone knows that problem?. Which is their nature and the cause of it?
- There are any solution or improvement possible? Which ones exactly?
- Can myself perform any action to alleviate or fix the issue?
- It's a problem plaguing the whole LCD technology, the NEC brand, or just I have had bad luck with my monitors?
Thank you very much in advance
Attached Files
No problem to wait a little more.
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