Discussion in 'Projectors, Screens & Video Processors' started by Timh, Nov 22, 2001.
See here for av-sales comment on dead pixels. under data/video projectors.
I must admit I find these replies from manufacturers who quote what is 'acceptable' as far as dead pixels go, ludicrous!
I mean, if I buy a product I expect it to work 100%, not 98%, not 99% - I dont care how 'minor' they perceive the 'defect' to be, if its not 100% I want my money back or a new product.
How can they get away with it.
This is one issue I have with purchasing an LCD projector (after researching for the last 6 months or so) with attitudes like this is doesnt fill you with confidence.
Whilst I can sympathise with those who, having shelled out a few thousand on their new hardware, expect perfection, in the real world perfection is rare. In reality, the manufacturing process isn't perfect and in any given run, a proportion of LCD panels will be discarded. As buyers, we have to pay for the bad ones as part of the price makeup of the equipment. To guarantee perfection, prices of such hardware would need to be higher, to account for a higher discard rate.
My WV10HT has one blue and one green pixel failed in the on (bright) state. I have not found any that have failed in the off (dark) state. The latter are much harder to see, anyway.
In truth, the blue pixel can only be seen from within about 2 feet of my 8 foot screen. The green one can just be detected at normal viewing distance, about 12 feet. But you have to know where to look. Even knowing this, I can still "lose" it. I have shown people (with good eyesight) my system, have told them that there is a visible bad green pixel, and NOT ONE of them has been able to see it from normal distance, unless I mute the picture signal and then point it out, and then "only just..."
In the circumstances, IMHO, it would not have been reasonable for me to demand a replacement - the flaw does not detract AT ALL from the experience and is not visible in normal use. Which is why I feel that manufacturers are somewhat justfied in their approach.
Of course, the lack of a defined and consistent policy on what is, or isn't acceptable, is frustrating, and I don't know what would have happened if there had been more bad pixels, perhaps grouped together, and perhaps in a more central part of the image.
I have just taken the plunge and bought my first PJ. Sanyo PLV-30
When I got it home and powered it up , guess what, it had 2 bad pixels near the top right hand corner. I bought the unit from Seven Oaks in Glasgow, who inturn phoned Sanyo customer helpline.......who informed that the 2 pixels loss was in fact within the spec for the PJ........!!
As you can imagine I was not to happy with this reply
Now it maybe that Sanyo see this as a lower end unit.......but to me it is 2 grand worth of investment and I expect for this amount of money a 100% quality item.
The chap at Seven Oaks was cool about it and was totally understanding of my point of view and would try and source another unit for me.
The point he made on the phone to Sanyo that how is he suppossed to sell their products with replies like this, I never heard the reply............
When I bought my PLV30, 2 months ago, I had to deal with this problem.
The first unit came with 2 dead pixels and I had to use my best diplomatic skills (as meager as they may be
) in order to overcome this silly Dead Pixels Policy (DPP) and get a flawless 2nd one.
The Sanyo sales rep told me that Sanyo considered the units to be in an acceptable selling condition up to 0.001 dead pixels. For an 800x600 panel resolution, this equates into 480 pixels.!!!
I can not agree with Nigel on this one for a couple of reasons, which I also used to persuade Sanyo into replacing my PLV30.
LCD projectors come from a lineage aimed at the presentations market. Most probably this DPP was created under this light. In reality, it is not very important, for someone making a presentation, lets say, in PowerPoint, that some pixels are missing from the picture.
However, the Home Cinema (HC) crowd took a keen interest in these projectors and, nowadays, it is a significant path in the total volume of sales. In the particular case of the PLV30, it is clearly market-targeted for the HC market, as the DV Theater " logo on top of the box, along with features such as component inputs and progressive scan, clearly demonstrates.
For most HC users it is very important that the unit does not have any dead open pixels: If the film contains a starry night scene, it will only be one more filling the sky. But, If, on the other hand, the scene displays, lets say, a panther, it will be rather silly watching it moving around with a couple (or up to 480!) little light spots flashing through the body!
Also, DPP is ridiculous because its perfectly arbitrary: 0,001 seems to be the magic number with Sanyos. Why not 0,003, or 0,01, or any other value? Is it really up to the manufacturer to decide?
And last, but certainly not least, consumer law is quite clear and uniform over the EC, in respect to this: The sold product has to (A) serve the end for which it was acquired and (B) be exempt of defect.
Dead pixels fully fall into (B) above and it can be argued that they do not comply with (A) for the parts of the films that they will affect.
Lets not let this guys get away with this. It is really pretty simple: Do not part away with your hard-earned money until you are satisfied with the unit (In my case this was surely a main factor, since I had not paid for the projector yet
). If we all reject affected units, their policy is bound to change.
Lets not loose perspective here: even a scratch in a 15 pounds toaster outer casing is reason enough for trading it in
good point, I totally agree with you on that one.
It would be interesting to know the cost to manufacture an LCD panel, and if cheap enough it could be replaced ,if defective under the quality control testing, thats if they have a quality control implemented.
I am soon to be investing in an Hitachi LCD projector, but I cannot find thier policy on the replacement of a projector with dead pixels, the likes of Sony and Sanyo advertise thier policy on thier literature.
Sanyo's being. At least 99.9% of the pixels are effective.
Personally I find it amazing that any dead pixels in a new projector can be considered normal by manufacturers.You can picture it now down at the car show rooms "Smashing motor mate,has 4 wheels as a rule unless it comes with three" Yea,right!
I recently bought a Sony VPL-VW11HT after seeing a demo. The PJ was one of three the dealer had taken delivery of that day and were the first of the new model. I got it home and set it up on a coffee table for a quick test run. The screen is a Stewart GrayHawk so I was looking forward to some significant black level improvement over the model 10. Toy Story 2 went in the dvd player and I settled back waiting for my jaw to hit the floor.
My jaw was well and truly embedded in the shag pile but it wasn't the black level that was responsible. Against the blackness of space I could see a dead pixel (the worst, a blue 'un) which was screaming at me from the screen. On closer inspection it actually turned out to be two of the buggers side by side.
The PJ went back the next day and in fairness I was treated bloody well by the shop staff, Audiovision of Brighouse, West Yorkshire take a bow. I swapped it for the demo model which I knew to be perfect and now look forward to my molars hitting the Axminster for the proper reasons.
I was lucky, many are not. Sorry Nigel but a dead pixel is truly bad news man 'cos I guarantee once you can see it you are drawn to it every time and that spoils the whole cinematic experience for me. If manufacturers can achieve 99% of panels free from dead pixels then its good enough to offer a no questions asked exchange if you are unlucky enough to get them.
Now, if you buy on the net or mail order you are in a lottery, you are taking a chance on the unit working perfectly out of the box. Me, I bought from a dealer for a few hundred pounds more but got the service that got me out of trouble. The lesson to be learned here is simple. Buy from a dealer, spend a bit more and ask to see the product working before you part with cash. A saving of two or three hundred pounds is tempting but I'm glad I spent the extra as I'm a very happy bunny now.
The first projector I saw in a dem, about 3-4 years ago was a Sharp 380H. It had 4 or 5 dead pixels in a sort of L shape, right in the middle of the screen. I questioned what this was, and was told that this was a normal thing with LCD projectors, and that most people don't notice it Salesman eh? This put me off strait away.
I have heard of stores replacing units for having one dead pixel, and others won't replace anything for under the tolerance. So I guess you would need to clarify this before handing over your cash. Its certainly not acceptable to me when spending thousands, or even hundreds of pounds. If there is something not right, it should be sorted out or changed.
I'm afraid I have to go back to......
Its all a matter of cost. We all (well, most of us, anyway) put up with CRT TVs with geometry and convergence errors and voltage regulation "bounce". CRTs CAN be made nigh-on perfect, but they aren't because it would cost too much.
It may well be true that dead pixels is a more "intrusive" artefact than those that plague CRT TVs, and it is certainly true that the lower-resolution the panel the bigger (and hence more noticeable) the pixel will be. And I'd definitely agree that two or more adjacent ones, and any that are central to the image area, especially green (actually, green are the worst) ones - are unacceptable.
However, when I read posts on this forum about "where can I get a PLV-30 for 99p less than wherever else" it is easy to see why manufacturers are inclined to keep their costs (and hence prices, and hence quality) as low as they think they can get away with.
Perfection costs. That is my point. And the person who pays for it is.........you and me.
Maybe what manufacturers should do - not just with LCDs but with pretty much any piece of equipment - is to offer each model at two prices - first class and second class - to give buyers the choice of either getting (close to) perfection at a premium, or getting an "average" product - such as we do at present, at a discount.
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