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Discussion Starter · #1 ·
So heres my problem.


A few weeks ago I started to notice a large 3ft circle in my image. It was not too noticable, but it created a slight discolouration in the image during some scenes. It did not affect the picture significantly, it only changed the shade slightly different, just enough to notice. It did not go away so I figured it must be a dust blob.


I took the pj into a Sanyo dealer and they did the compressed air thing and checked the image...it looked fine at their shop.


I set it up again and first thing I did was check some familiar scnenes for this circle. No circle...hurrayy!!!


The next night eg. tonight I started watching a DVD and noticed the circle back again in the exact same spot. Same symptoms as before.


It hard to believe that its a dust blob again in the exact same location. I also thought it may be some type of ambient light hitting the screen but did a full check and there really is no other light present. Another thought was the source material I was playing. So first I tried it on my DVD player through the projector (versus my htpc)...same problem. And then I tried the DVD on my CRT TV...no circle.


So I have concluded it is the projector or some other external factor that is creating this. I am quite confident it is not the source material and also it is not a dust blob, given it is in the exact same location.


Open to any ideas?
 

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Something similar happened to me the other night, but it was straight line across the middle of the screen, slightly darker than everything else.


I concluded that it was leftover from a dvd that I had been watching previously. I had been calibrating my sub using Avia (Chapter 7). This screen has a line that goes across the middle. Apparently, I had left this screen on for a while.


It was weird. It looked like RPTV burn in.


This might not be your problem, but something to think about.


Does you DVD show a 3ft circle logo when there is no disc loaded?


Again, I'm just shooting in the dark here.
 

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Discussion Starter · #4 ·
hmmmmm, burn in. yes this is exactly what it's like. i can't think of any circular logo and I'm quite careful not to leave a static image on for any given period of time, but I will have to give it more thought.


thanks for the ideas
 

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You cannot get LCD-panel burn-in. The only analogous think would be some sort of actual panel damage that was caused by some sort of massive failure.


Mark
 

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How about this problem being related to the lamp. If the lamp surface has a hot spot on it and or mercury vapor is collecting on the surface this could in fact deminish the lumen out put in this area. What do you think.
 

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Discussion Starter · #7 ·
What I find strange is that when it was set up at the Sanyo shop after they did the compressed air thing the image was fine - no circle.


When I came back home, it was there again. I tried a few different DVDs both on my RP-82 and HTPC and it was there. I will have to try out a few more DVDs tonight because I'm not positive it is present with every DVD...only some. Its almost like it comes and goes, but appears in the exact same location on the screen.


What I think I can conclude is

- it is not the DVD player - the problem exists on both my RP-82 and HTPC

- it is not a dust blob - too big and what are the chances of getting a dust blob in the exact some location twice


What I am not sure of is

- is it the projector? - at the Sanyo shop it was perfectly fine

- is it the DVDs?

- is it some external light source hitting the screen?


Anyway its got me baffled at the moment but I will do more testing tonight and post any additional findings.
 

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Just another wild guess. Do you have a screen or are you projecting the image on a wall? If on a wall could it be the tecture of the wall? Do you have a SO. playing some kind of trick on you? Did you by chance touch the lens when you readjusted the Pj for your room when it came back from the shop? Good luck.
 

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Discussion Starter · #9 ·
I project onto a Dalite High Power screen which has no imperfections. I have cleaned the lens as well.


Thanks for the ideas.
 

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One more and I will let you rest. I started to wounder if it is a certain color? Maybe it is one of the panels. Maybe you could try and remove the lamp and see if there is dust in this area. And at the same time you can inspect the lamp surface it self. Thats about it for me. But am curious as to what fixes it. I will check back and see what you find. Have fun.
 

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Just to be 100% sure it's not your screen, I would try turning or tilting the projector and checking to see if the circle follows the projected image or stays in the same place on the screen. There is a possibility that there is a flaw in your screen that you can't see under normal lighting conditions.
 

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good thinking I must be tired.
 

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Discussion Starter · #13 ·
OK, i have played around with it for an hour and here is what i've found


- definitely not the screen. when i move the projector, the whole image including my mysterious circle moves with it.


- the circle has blue tint to it and is most noticable in only 10% of the sceens. sceens like underwater shots in U571 or in Jurasic Park when the kid was in the giant bird cage and there was a fine mist. also noticable in people's flesh tones. the other 90% of the time you can't even see it, although I strongly believe its still there. there is no loss of image quality within the circle, only a slight change in shade..towards blue.


So i am quite sure that

- it is not the DVDs or material - in one sceen or another for every DVD i've tried it shows up and I have tried some on my CRT TV and no circles appear.

- it is not an external light source hitting the screen - circle moves with the image


So I am lead to believe it is something to do with the blue LCD panel. Not sure what and not sure how to correct it, but it may require another trip to the Sanyo shop....ughhh.
 

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it is something on the blue panel. it still could be dust even though you don't think it is. I have had dust blobs before where I blasted the panels and it appeared they were gone but after a while a blob showed up in the exact same spot.


defocus the pj and see if it is dust or some foriegn object that might be on the panel. you'll know if it is this because whatever is there will come into focus.
 

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Discussion Starter · #15 ·
i really hope it is something simple like another dust blob, stay tuned...
 

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Discussion Starter · #16 ·
So I took it to the Sanyo shop today and they hooked it up and sure enough the blue circle was present. As mentioned it only is visible in certain scenes (water, flesh tones etc.).


They said that this was no uncommon for LCD - they said it was a color uniformity issue and would likely not be fixable or go away. While I heard many times on this forum people talking about color uniformity issues with LCDs in general i did not think my blue circle was in fact this problem. They agreed to send it to the shop to see if they could fix it, but made no guarantees. In his opinion they would not be able to do anything.


What disappoints me is that this circle was not present up until now (eg. +100 hours) and now it could be there for good. Because its not visible all the time (eg. only 10% of scenes) it is not that irritating, but knowing me it will drive me crazy over time. While I can accept this is a inherent characteristic of LCD, having this circle there is just no acceptable and I feel as if Sanyo should do something to address the issue, rather than rely on this reasoning. Perhaps my expectations are too high. We will see what they come back with and hopefully they will be able to fix it and/or replace the panels.


Looking forward, if they are not able to fix, I may consider selling and buying DLP or higher end LCD.


Will DLP have similar issues? Will a higher priced LCD's have a smaller chance of experiencing this same problem?


Appreciate any advice.
 

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Look for in the Rich forum (+5000$ projectors).


Other people have the same problem with the Sanyo PLV-70.


It seems that this problem appears and desappears.


Do a search.
 

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Discussion Starter · #19 ·

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Discussion Starter · #20 ·
Update,


My Z1 is at the Sanyo service centre and I should get it back in a few days.


I called the Sanyo service centre in Canada (as its difficult to communicate here in HK) and they provided some good information. Based on my symptoms they are quite sure it is thermal heat damage to either the Polariser, LCD panel or some type of dicromic mirror thing. Of course they cannot be sure provided my explaination was over the phone, but he seemed quite sure thats what it was. Basically the cause of this is overheating.


What surprised me was that he said this would not be covered under warranty which is absolutly ridiculous. I explained to him that I have not changed any of my temperature settings and have been running on econo mode for +100 hours. So if the pj does not detect the overheating and kick the fan into high gear, how I am I suppose to prevent this type of damage from happening?? Really he had no good answer and said that HK warranty may be different. Well we'll see, but if this turns out to be the problem and it isn't covered, I could be in for a battle that I'm not looking forward too. Primarily because it's so difficult to communicate here.


Anyway in one sense I feel partially relieved because I finally know what the issue is and it appears specific to Sanyo projectors only (as far as I have heard).


Looks like I could be on the market for a new pj.....oh well:D how do i explain this to the wife:( :confused:
 
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