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Discussion Starter · #1 ·
Last night I did something rather stupid - I fell asleep while watching a DVD on my Pioneer 503cmx. (In my defense, I was tired.) A couple of hours later I wake up to find the movie over and the DVD returned to the main menu. I turn off the DVD, and the image of the logo and text on the menu is clearly visible on the screen. I think - no problem, I've read a million posts here about burn-in issues, and know that permanent burn-in cannot happen in that short a period of time; it is ghosting, and will go away when everything cools down. I turn of the set and go to bed.


This morning I turn on the set, and the logo and text are just as visible as last night. All of a sudden I am sweating a little bit. (We have only had this display for about six weeks - too early to explain to the wife that I f'd up and she is going to watch this thing for the rest of her life with a Planet of the Apes logo on top of regular programming!) So I think - I know, I'll see if I can white-mask this image away. To make a short story long, it worked. About 30 minutes of the white mask did the trick. (Unfortunately, it did not 'turn' my one stuck pixel, but I can not detect this outside of the white mask anyways.)


My questions to the gang are:


Was this truly ghosting which should have gone away after watching whatever programming for a while, or is this closer to a burn-in kind of situation? I am guessing ghosting, since burn-in as discussed on the forum is permanent, which this was fortunately not.


If it is ghosting, any idea of how long you would have to watch regular programming to make the image go away? (It is true that I could perform an experiment by recreating the situation and discovering the answer on my own, but don't think I will!)
 

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fizbin:


Relax, it's normal. It would have gone away just watching a full screen picture for a while. Running the white mask does the same thing, of course. It's just more difficult to use because of getting into Integrator Mode and playing with the settings.
 

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maybe next time it would be better to play some full screen tv straight after you notice it rather than in the morning after
 

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Some DVD players have screen-saver modes to prevent burnin from "falling asleep" - check if yours has such a feature.
 

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I've seen a lot of threads and posts on this problem, and I admit to having the same fear before I took the plasma leap. But I have to ask - has anyone, in a normal home theater application (as oposed to some computer driven commercial application) ever experienced a permanent burn-in artifact on their screen?


While I may be proven wrong, I have my doubts that anyone, even someone who mixes letterboxed and 4:3 viewing, has ever seen this as a permanent problem. Of course there's a short term gosting problem that occassionally shows itself - but this is temporary.


If no one reports a substaintial burn-in experience using plasma with the normal mix of home theater viewing, then it's time to put this issue to rest and make correct claim that this is not a plasma issue or problem.


Just my $0.02...
 

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i see these threads all the time and usually do not post, but i have to agree. i got my first plasma almost 4 years ago and have made every mistake imaginable- including leaving the PC desktop display on screen accidentally when my screensaver had been turned off- and have never had any lasting problems. i think you have to work pretty hard to cause permanent damage.
 

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Discussion Starter · #7 ·
Thanks one and all for confirming that my stupidity (at least in this case) will not cause permanent damage. I'll try to watch more interesting movies that can keep me awake to the end.
 

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Permanent burn-in is caused by uneven phosphor aging, where, using a uniform white field input (for example), phosphors that have been highly illuminated show less brightness than those that have not.


Given that plasma half-lives have been estimated at 20,000-30,000 hours, this indicates to me that phosphor aging on plasmas happens quite slowly. Therefore, burn-in should not be much of a problem, and there should be no mysterious mechanism that makes them burn in faster than CRTs.
 

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Quote:
Therefore, burn-in should not be much of a problem, and there should be no mysterious mechanism that makes them burn in faster than CRTs
Actually the mysterious mechanism is the fact that plasma tv's use UV light to excite the phosphors instead of cathode rays used in crt televisions. The UV light causes the phosphors to decrease in brightness quicker than a normal crt, hence why burn occurs quicker on plasma displays.


The ghosting effect is bascially a semi permanent ionisation of the plasma gas, if a pixel is consitantly charged bright it will be slightly more ionised than the other surrounding dark pixels, which gives the ghosting effect, these charges can last for several hours when the plasma is off which is why you still see it in the morning. Just watching some normal video for a couple of minutes this will charge/discharge the cells which will bring the base ionisation of the cell back to normal levels and in line with the rest of surrounding cells.
 

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Neomoz, what you say about burn-in is true and false. It is true that the phosphors are excited differently. It is true that they therefore wear differently and perhaps faster. What isn't true is that they wear quickly. I'll take Pioneer's 30,000 hours to half brightness as an indication that the useful life of my plasma far exceeds any reasonable amount of time for me to consider it my primary display.
 

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Quote:
Originally posted by neomoz
Actually the mysterious mechanism is the fact that plasma tv's use UV light to excite the phosphors instead of cathode rays used in crt televisions. The UV light causes the phosphors to decrease in brightness quicker than a normal crt, hence why burn occurs quicker on plasma displays.


The ghosting effect is bascially a semi permanent ionisation of the plasma gas, if a pixel is consitantly charged bright it will be slightly more ionised than the other surrounding dark pixels, which gives the ghosting effect, these charges can last for several hours when the plasma is off which is why you still see it in the morning. Just watching some normal video for a couple of minutes this will charge/discharge the cells which will bring the base ionisation of the cell back to normal levels and in line with the rest of surrounding cells.
Please note the I stated "permanent" burn-in my post, as opposed to temporary ghost images that disappear with anything from a few minutes to a few hours of normal use.


If UV light did indeed cause phosphors to decrease in brightness faster than a normal TV, we wouldn't see the very high 20,000-30,000 hour phosphor half-lives specified on current plasma panels.
 

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fizbin - Your experience is pretty close to what happened to me as far as the display is concerned. After still seeing it if I looked carefully enough after one week of normal use (about 2-3 hours per day), it appeared to quit fading and I was certain it would never go away. Another week later and it was quite hard to see. It's been another week or so since, and I can't find any evidence of the image even if I turn off all the lights and look at a black signal.


Don't panic like I did. Unless your fingernails were significantly longer when you woke up, it may take a while but it will eventually work itself out.
 
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