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Discussion Starter · #1 ·
Today I noticed a line all the way across my screen. It is in the center of the screen vertically. I turned off the tubes on by one and found that it was only on the red tube. I suppose the tube burned a line on the phosphor. These are new tubes and I got the unit from Projection systems where they have a 1 year warranty. Why would this happen? It is certainly not screen burn in from an external source.
 

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Make and model of the patient?


Marc
 

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You do not state if this is a bright line or a shadow line, if the line is dim it could be a burn in, look into the red tube with a flashlight if you suspect a burn-in.


If the line is bright, its probably some setup problem, on Barco's the line becomes visible if the electronical menu settings are driven to extremes.
 

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Discussion Starter · #4 ·
It is a 6PG Xtra. I just did a test and it appears on all my memory locations including the svideo input. I looked into the tube and I see the line but it is not bright but dim.


I have not had any video source running externally that could possibly burn this in.
 

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Look into the tube with the power off. If you see the line, then the H scan failed on the red tube and the set needs to go back.


Curt
 

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Discussion Starter · #6 ·
With the power to the pj off I see nothing because it is too dark. Should I turn the lights back on? Kidding :)


When I shine a flashlight into the red tube I cannot see the line. Do you mean turning off the red tube only by the remote or turn off the power completely.
 

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Turn off the power completely. You can also try moving the raster and see if the line moves with the image or not. If it moves, it's not the tube.


Marc
 

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Discussion Starter · #8 ·
I did a picture shift from the remote and the line does not move. I muted the picture and the line was visible looking in the tube. I turned off the gun and the line was there. When I turn off the power though I can't see much shining a flashlight into the tubes.


I think the tube has a problem that I can't fix. Shipping this beast back will be a pain in the ass as I have to tent a genie lift again to get it off the ceiling etc etc. Will these types of problems get worse it is is a H scan failure? Maybe I can live with a thin line across the red tube for now if it does not get worse.
 

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Guys!


I have no real experience with NEC products but burn-in due to collapsing sweep suggests a problem in the spot-kill circuit also. Spot-kill is a required function with any CRT system because you can have, at power-off, high voltage and beam after the H or V sweep collapses. If this happens then you have too much beam concentrated on very little phosphor, this results in a line burn or spot chunk burn; do not replace a tube in this case unless the spot-kill is proven to be working. Typical spot-kill is a logic signal sent to the neck board or drive card to slam the video into deep black as the unit powers down, one could have a bad drive card for one color CRT, or lack of logic signal causing all three tubes to scar.
 

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Sounds like a tube burn in . NEC's are usually pretty good at eliminating dots or lines burnt into the tube due to scan fail, but if the screen circuit had/has a problem, then it can do it.


I did have a freight damaged set cause a dot to get burned into each BRAND NEW NEC tube recently...:-(


Curt
 

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Discussion Starter · #11 ·
But does it get worse over time. I just finished watching hdnet and let me tell you I am so happy I went crt. If I think about the line I can see it if I look hard enough, if I enjoy what I am watching then I forget its there. As long as it doesn't get worse I can live with it.


Maybe I need to change the board just to be safe. What board would that be? Is it easy to replace?
 
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