AVS Forum banner
Status
Not open for further replies.
1 - 20 of 25 Posts

·
Registered
Joined
·
760 Posts
Discussion Starter · #1 ·
Hi there!


Just when I was getting all worked up in a frenzy and really enjoying my G-11, guess who finally showed his puss at the door... http://www.avsforum.com/ubb/frown.gif


This is terribly annoying. I now actually have two always stuck-on red/magenta colored pixels (or blobs, cause these things look bigger than a pixel to me). One is to the left of center picture, and the other is way up above the 16:9 frame so is hidden when viewing widescreen material. The one center-left is getting on my nerves and is quite distracting.


What is JVC's policy re. dead pixels on their D-ILAs?


What constitutes "acceptable" to you? To me it is obvious. I had no dead pixels for the first 100 hours or so. After 100 hrs, I now have two. This technology presents a huge shortcoming if this is considered allowable. It can't be right that this happens right into the life of the machine first of all, and in such a short time to boot. To me this is unacceptable! It's like you were told you had a 50-50 chance of getting stuck with it at some point in time during use. I don't know about you, and I don't know about the exact percentages of probability here, but it just does not entice me much to gamble when the odds are this high against me at the start of the race.


If this is life with this beast, then I have to seriously reconsider the D-ILA projectors that I have enjoyed so much in the past months, to be a technology worthy of upscale cinema quality at home. I simply cannot buy into this knowing that this will happen one day.


Sorry for the rant!


Luca
 

·
Registered
Joined
·
2,314 Posts
If they are truly dead/stuck pixels, I think they would be clearly visible as a single pixel rather than a blob. Are you sure you aren't just seeing dust in the light path? I know this has been a 10HT problem, but I would guess it can happen to other projectors, too. On the Sony, you can tell if it's dust by defocusing the image. If you defocus far enough, the dust will usually come into focus and you'll see it as clearly as a speck of dust.


------------------

Steve

Visit our dedicated home theater, The City Cinema.
 

·
Registered
Joined
·
760 Posts
Discussion Starter · #3 ·
Steve,


They look like pixels to me, as they are sharply defined in their corners. I have never seen dust blobs, but aren't they more like an amorphous fuzzy mass than a pointy dot? Please correct me if I'm wrong. I'd like to know what I'm seing first. And assuming it is dust, does it have a solution?


Luca
 

·
Registered
Joined
·
287 Posts
Dust won't show up on an all black screen as a lit pixel. A stuck on pixel will always be on, and will only be pure red, green, or blue. It's possible for the exact same stuck on pixel location to be a mixture of colors, but the chance is very, very remote.

I've noticed some dust spots when I project a pixel by pixel checkerboard. That's the only way I can see them though.

I sincerely hope for your sake it's only dust. Dust should be an easy fix.

Jeff
 

·
Registered
Joined
·
707 Posts
To determine if it is a stuck on pixel you can disconnect one cable at a time (I am assuming that you are using an RGB source.) When you eliminate the offending pixel on the screen you have disconnected the cable to the panel driving that pixel. Regarding stuck pixels most manufacturers use the same general rule that if you have 1 stuck on pixel in the "A" zone (an area in the center portion of the screen) they will repair change the bad panel) or replace the projector. If the pixel is out in the "B" zone further away from the center you need to have several stuck-on for them to consider replacement as an option.


Generally speaking pixels will be stcuk-on from day one with a projector and will not appear later on in life. This is certainly not cast in stone as you could certainly lose a pixel on a panel due to malfunctioning electronics or damage possibly due to heat build up from poor ventilation.
 

·
Registered
Joined
·
2,926 Posts
Luca,


I have the same problem as you with my G15. I think I may just send it in to JVC. Any stuck pixels close to center are considered a defect. The only problem is that JVC takes a long time to service and replace the panel.


I can see the pixel alot and it does bug me. It is the only complaint that I have about the projector. Oh yeah, I don't like the halo too much but I will be changing that soon with a masking system at the projector.


Cameron


------------------

-- Well I have really blown my budget now. --
 

·
Registered
Joined
·
287 Posts
Ken,

From all the talk around here about ripping into 1 chip dlps to do some dusting, I figure it's possible to do the same thing with a d-ila projector. I haven't done it yet or remember any threads addressing the process, however. My dust isn't enough of an issue for me to send it back for warranty repair. I'm scared they'd send another projector with stuck on pixels, instead of mine with 2 unnoticeable stuck off blue ones. If the problem was really annoying and it was past 1 year, I'd take a shot at it. Even if it came down to sending it to JVC, removing some dust will be signicantly cheaper than replacing panels.(out of warranty)

Jeff
 

·
Registered
Joined
·
1,501 Posts


I try very hard NOT to make a critical examination of the projection when my G15 is showing a solid color or the like. I know that once I actually see a dead pixel I will always see the damn thing.
 

·
Registered
Joined
·
2,926 Posts
Luca,


Unfortunately my stuck red pixel is about 8" off center to the righton an 8'wide screen. I notice it a lot!


As for the spec, I read it on this forum. It seemed like there was a radius from the center that no pixel would be acceptable. I think that the radius encompased about 70% of the projectors pixels. It also mentioned that if there were two next to each other it would be out of spec.


Hope this helps.


I would like to have them service it, but I worry that it will come back worse. My one stuck pixel is the only problem pixel on the whole projector.


Cameron


------------------

-- Well I have really blown my budget now. --
 

·
Registered
Joined
·
287 Posts
Cameron,

One stuck on red pixel would drive me to dlp. I'd take the risk and send it in for service.

It's not a G1500M, is it? If it is, nevermind...

Jeff


[This message has been edited by JSC (edited 04-02-2001).]
 

·
Registered
Joined
·
462 Posts
What would the result be if you pasted a black dot on the screen exactly where the stuck pixel is located? Just curious. Of course if this helps it would require the projector's position to be fixed.


Tony C
 

·
Registered
Joined
·
185 Posts
I bought the last NEW G11 last week from AVS and tried out my projector Friday night at my friend’s house who has a G11 and a 9 foot screen. Im saddened to say Mine has a stuck on Blue Pixel just slightly to the right and slightly down of center.


We measured and calculated its position at Pixel 954 from the left, 411 from the right ((1365 Horizontal) and Pixel 602 from the top, 422 from the bottom (1024 Vertical This is going to BUG me knowing its there. When a black scene is on it shows up very noticeably, so since My theater is not ready for viewing yet and I paid large $$, I can send it in to be fixed. What are my options? I will call AVS on Monday. Bummer it was looking so nice........Chuck


 

·
Registered
Joined
·
760 Posts
Discussion Starter · #15 ·
Yeah, once you notice one, it is hard to not look for it during a movie, and it is really really annoying. I'll do some research on what JVC's exact policy is regarding this. I just hope that if they service it, they don't screw up the perfect Richard Martin calibration.


I can really see now the arguments CRT folks use to enforce their point that their technology is superior. For the life of me, I can't possibly think how anybody here that's a videophile be contempt with such an obvious distracting defect. Not only it drives you nuts, but the very fact the fault is there to begin with cannot by any means of the imagination make this technology superior to CRT, all other things being roughly equal.


Luca


Dissapointed,


Luca
 

·
Registered
Joined
·
185 Posts
Yes, Mark the pixel is always on. We measured the location with a tape measure and my friend did the calculation. It is very close to the co-ordinates I have listed above. It would be great to turn it off, let me know if your sw can do it...I can see it mostly in a black scene...Im going to see what JVC will say on Monday..

I wonder how many others have a similar problem and has JVC been able to fix them... I just received this projector 2 days ago...Chuck
 

·
Registered
Joined
·
106 Posts
Re: Finding a pixel's exact coords:


Why not just load up a program like paint or photoshop, and expand the canvas to fill as much of the screen as possible. Then, figure out the amount of pixels from the top left hand side of the screen to the beginning (top left) of the canvas (for me, I just counted them manually) and label this your "offset."


Both paint and photoshop have a coordinate display on the status bar, where they tell you what pixel the cursor is pointing at. If you added that number to the offset you calculated, you could get the exact pixel location of a given point on the screen. It seems that you could use this to determine exactly where a faulty pixel is if you have the PC hooked up to the projector and you are running a 1:1 resolution.


'Course, not having a D-ILA myself yet, I can't tell you whether this actually works or not, it's just an idea =) However, if this does work, and if Mark can come up with a way to permanently turn off a given pixel, this would be a most excellent solution to the dreaded always-on pixel problem.


paulb
 

·
Registered
Joined
·
4,525 Posts
Exactly.


I don't know if it will work without testing it, but it's worth a try the next time I turn on the projector:
  • Using a flat black field and a white mouse cursor, simply point to the pixel that is stuck on. A stuck on pixel will show up best on the black field, whereas a "dead" pixel would show up best on a white field.
  • The pixels coordinates are translated into the position for correcting the pixel inside of the projector (I have 2 ideas to try out to do this).


I wouldn't put too much faith in this yet...it is possible that the solution would create other issues that are worse than the original problem! I will let you know after some testing.
 

·
Registered
Joined
·
4,525 Posts
Hi Chuck,


Pixel 954 from the left, 602 from the top.


Since you know the exact pixel location, I wonder if we could turn your "always on" blue pixel into a much less objectionable "always off" blue pixel. It is really hard to see a single color element being off among the 4 million of them available.


I am thinking about how to turn that one pixel off, and I think that it might be possible since you know the location of it.


It is "always on", correct?
 
1 - 20 of 25 Posts
Status
Not open for further replies.
Top