Author Topic: DELL Ultrasharp 2408WFP Shadows  (Read 10250 times)

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Offline hgg

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DELL Ultrasharp 2408WFP Shadows
« on: November 24, 2013, 01:18:19 pm »
Hi guys,

I have been using this monitor from 2008 and it served well with excellent images but the last
year it developed some shadows on the right side of the screen that are more pronounced
when the monitor is just switched on.  When it warms up they fade a bit but they are clearly
visible.

Has anybody had a similar problem?  Do you know if is it serviceable?
Thank you.

(you can see the shadows in the right lower side of the image)


Dell LCD Problem
 

Online PA0PBZ

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Re: DELL Ultrasharp 2408WFP Shadows
« Reply #1 on: November 24, 2013, 01:55:33 pm »
If it gets better when warming up it could be the CCFL lamps reaching end of life. The picture is not very helpful for me though.
Keyboard error: Press F1 to continue.
 

Offline SeanB

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Re: DELL Ultrasharp 2408WFP Shadows
« Reply #2 on: November 24, 2013, 02:00:02 pm »
Time for new CCFL tubes there. They are blackening and this will eventually get to the point where the inverter will shut down.

While you have it apart you might want to look at the PSU capacitors and change the worst ones.
 

Offline nctnico

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Re: DELL Ultrasharp 2408WFP Shadows
« Reply #3 on: November 24, 2013, 02:04:52 pm »
IIRC I still have a TFT panel for this monitor. The PSU developed bad solder joints which caused the output voltage to rise way too high. It wrecked the 5V parts on the controller board.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline hgg

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Re: DELL Ultrasharp 2408WFP Shadows
« Reply #4 on: November 25, 2013, 06:58:14 am »
Hi,

Sorry for the late reply.  We had yesterday very heavy rain, blackouts and no internet....
Thank you for your replies.  Please have a look at a slightly better picture that shows the problem
better.


Dell Shadows

These shadows do not change place.  If it was the CCFL wouldn't it be more black at the far right
end of the screen?  The middle right is still white.

Thanks.
 

Offline marshallh

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Re: DELL Ultrasharp 2408WFP Shadows
« Reply #5 on: November 25, 2013, 10:15:07 am »
Probably condensation residue (precipitate?) on the inside. Could be inside the LCD panel (between glass and plastic light diffuser sheets) or on the outside of glass, or inside the display antiglare layer if there is one. Take it apart and clean it?

Also, I see somebody's extracting a certain popular CAD package :)
Verilog tips
BGA soldering intro

11:37 <@ktemkin> c4757p: marshall has transcended communications media
11:37 <@ktemkin> He speaks protocols directly.
 

Offline hgg

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Re: DELL Ultrasharp 2408WFP Shadows
« Reply #6 on: November 25, 2013, 10:44:10 am »
Hi marshallh,

That's what I thought as well in the start, but I wasn't sure.  The monitor gets warm, and it
works 24/7, so any humidity would have been gone, or at least the pattern of the shadows
would have changed, don't you agree?  When I press on the shadows they don't change.

I also read that it contains 7 CCFL bulbs???  It does not look like a CCFL problem though.
http://www.manualslib.com/manual/227789/Dell-Ultrasharp-2408wfp.html?page=5#manual
Hard to find a service manual fro this one.

I was sure that I will get a comment about the unzipping...   :)
Only a few characters gave it away... Try before you buy.

 

Online Psi

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Re: DELL Ultrasharp 2408WFP Shadows
« Reply #7 on: November 25, 2013, 10:50:26 am »
The monitor gets warm, and it works 24/7

What does your desktop background look like? Does it by any chance have a pattern which matches the pattern on the LCD in that corner?

My 8 year old Dell 24" (similar model) is showing a pattern top-left which i know is burn-in because you can see some desktop icon shaped blocks in it.
« Last Edit: November 25, 2013, 10:58:26 am by Psi »
Greek letter 'Psi' (not Pounds per Square Inch)
 

Offline hgg

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Re: DELL Ultrasharp 2408WFP Shadows
« Reply #8 on: November 25, 2013, 11:06:15 am »
Hello Psi,

Its not a pixel burnout either.  The desktop background is different and on top of the shadows are
usually windows with even white or colour background.
 

Online Psi

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Re: DELL Ultrasharp 2408WFP Shadows
« Reply #9 on: November 25, 2013, 11:31:27 am »
What about during the parts of the 24h period every day when its not being used?
Greek letter 'Psi' (not Pounds per Square Inch)
 

Offline hgg

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Re: DELL Ultrasharp 2408WFP Shadows
« Reply #10 on: November 25, 2013, 12:11:43 pm »
Psi,  the shadow patterns do not match any of the images that I display on the screeen,
background or otherwise.  If it was a background imprint on the LCD it would have happened
elsewhere on the screen as well, especially on the left side were there are parts with the
same background 24/7.  Its only on the right side though, were the screen is changing
all the time.

It looks like a defect on the panel inside layers but I am not really sure.
 

Offline amyk

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Re: DELL Ultrasharp 2408WFP Shadows
« Reply #11 on: November 25, 2013, 12:17:27 pm »
That looks more like dirt/dust than anything else.

First thing to try (hopefully you've done it already) would be to wipe the surface... then you may carefully disassemble the panel and clean it.
 

Offline hgg

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Re: DELL Ultrasharp 2408WFP Shadows
« Reply #12 on: November 25, 2013, 12:29:35 pm »
The panel is clean on the outside...
It is no dust or dirt either. 
The shadows appeared abruptly after a 3 month period that the monitor was not used at all.
 

Offline marinedalek

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Re: DELL Ultrasharp 2408WFP Shadows
« Reply #13 on: December 04, 2013, 06:49:30 pm »
Where was it stored for that 3-month period? Anywhere that it could have been submitted to humidity/damp? It's tricky to tell from the images but it could be fungus, often also found in camera lenses. You can get anything from spots and streaks to a spidery haze (which you seem to have). The only way to fix that would be to disassemble and clean the display thoroughly. As you move your head from side-to-side, is the patterning in front of or "behind" the image on the screen? If the latter then the fungus could be in the diffuser rather than the TFT panel itself.
 

Offline envisionelec

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Re: DELL Ultrasharp 2408WFP Shadows
« Reply #14 on: December 07, 2013, 03:17:15 am »
The LCD stack is delaminating. There's nothing you can do short of replacing the panel. I had the same problem on a panel of similar vintage.
 

Offline hgg

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Re: DELL Ultrasharp 2408WFP Shadows
« Reply #15 on: December 07, 2013, 07:09:27 pm »
Quote
The LCD stack is delaminating. There's nothing you can do short of replacing the panel. I had the same problem on a panel of similar vintage.

Its bad news then...  :(

nctnico are you selling your panel ?...
 

Offline nctnico

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Re: DELL Ultrasharp 2408WFP Shadows
« Reply #16 on: December 07, 2013, 09:16:20 pm »
I looked it up. The panel I have is an LM181E06 (A4M1). BUT it seems I have harvested some of the backlight connectors from it and the surface has some scratches. All in all you would have to take the panel apart to exchange the LCD screen itself. You can have it if you pay for the postage but expect that to be in the ballpark of €27,- (plus some Paypal fees).

Maybe you are better off looking for a second hand TFT display with a defect. Usually its something simple like a blown fuse or bad capacitors.
« Last Edit: December 07, 2013, 09:19:00 pm by nctnico »
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline hgg

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Re: DELL Ultrasharp 2408WFP Shadows
« Reply #17 on: December 08, 2013, 07:40:02 am »
Hi,  but the LM181E06 panel is 18.1" and mine is 24"...
 

Offline nctnico

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Re: DELL Ultrasharp 2408WFP Shadows
« Reply #18 on: December 09, 2013, 06:25:19 pm »
I already typed 'IIRC I have a panel'. I'm sorry to be wrong  :'(
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline hgg

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Re: DELL Ultrasharp 2408WFP Shadows
« Reply #19 on: December 09, 2013, 07:02:56 pm »
That's ok,  I was happy for a second.   :)
 

Offline hgg

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Re: DELL Ultrasharp 2408WFP Shadows
« Reply #20 on: October 26, 2014, 11:47:12 am »
An update...


Dell 2408wfp

I am still using the same monitor and the problem remains exactly the same.
Yesterday  I tried heating up the affected region that has the dark shadows
with the heat gun and after a while the shadows were gone and the screen
had a uniform brightness again.   That did not last though.  Half an hour later
the shadows returned exactly as before!   >:D

So, it looks like that the damage has to do with the inside layering of the LCD .
Any other possible explanations?

Thanks.
George.

 

Offline wraper

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Re: DELL Ultrasharp 2408WFP Shadows
« Reply #21 on: October 26, 2014, 12:39:15 pm »
This is a backlight issue, polymer films dissipating light are damaged. Likely moisture got in and considering where you live, there could even be fungus grown inside. There is nothing you can do except replacing lcd panel or at least backlight unit which is not practical and moreover easy at all.
 

Offline hgg

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Re: DELL Ultrasharp 2408WFP Shadows
« Reply #22 on: October 26, 2014, 12:50:53 pm »
That's what it looks like.
I don't think that there is any fungus though because the monitor is always on and when off
the relative humidity is between 40-50%.   Also, when I heated the screen, the shadows disappeared.

Maybe one of the layers shrunk for some reason and it does not lay completely flat with the other layers.

It turns out that there are some times that you wish for bad caps... :)
Anyway, time for a new screen.
Thanks.

 

Offline wraper

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Re: DELL Ultrasharp 2408WFP Shadows
« Reply #23 on: October 26, 2014, 02:01:46 pm »
You wrote earlier that it was off for a three months. If fungus are grown, they won't disapperear. When you are heating, maybe fungus dries temporarily  :). Actually I don't know how much it is an issue with monitors. But fungus is very serious issue with DSLR optics.
 

Offline hgg

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Re: DELL Ultrasharp 2408WFP Shadows
« Reply #24 on: October 26, 2014, 02:04:55 pm »
My DSLR is in the same area and its fungus free.   :)
 


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