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Author Topic: Stuck Blue Pixels! Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 12-01-2014 04:54 PM                     Lately this is seeming like the plague. Have any of you had issues with stuck blue pixels on your dlp projectors? I have two units with this issue now and this past Saturday I went to a movie at a local Cinemark that has all 4K Barco's and there was a stuck blue pixel in that projector. Two of my service sites are also suffering from this issue, at one there is just a single stuck pixel running just a 2kw lamp, but at another it is really bad with multiple pixels stuck in different areas of the image and totaling 86 in all, they are running a H.O 4kw lamp. Would like to hear from others that have had this issue or at least seen it. I am hoping this doesn't turn out to be a big plague! Also, if you have had this issue what series projector was it in? Mark  |  IP: Logged Sam D. Chavez Film God Posts: 2153 From: Martinez, CA USA Registered: Aug 2003 posted 12-01-2014 05:27 PM                       New Christie 2220 mid last year, just a month old. Blue Old CP2000XB red. also this summer  |  IP: Logged Dave Macaulay Film God Posts: 2321 From: Toronto, Canada Registered: Apr 2001 posted 12-01-2014 06:07 PM                     The only one I know of is an NEC NC2000C with a blue pixel stuck on, fortunately just off screen (special venue). 4kW lamp, running 12+ hours a day non stop.  |  IP: Logged Allan Barnes Expert Film Handler Posts: 108 From: GRAND BEND, ONTARIO, CANADA Registered: Mar 2009 posted 12-01-2014 07:52 PM                        MARK HOW MANY HOURS ON THESE "BLUE" PROJECTORS?  |  IP: Logged Carsten Kurz Film God Posts: 4340 From: Cologne, NRW, Germany Registered: Aug 2009 posted 12-01-2014 07:55 PM                     Does anyone know about any stuck pixel issues ever been solved through on-site maintenance, e.g. formatter board, cable reseating, etc.? - Carsten  |  IP: Logged Marcel Birgelen Film God Posts: 3357 From: Maastricht, Limburg, Netherlands Registered: Feb 2012 posted 12-01-2014 08:13 PM                     I doubt that any damage to the formatter board or lose/damaged contact will yield in a single, fixed stuck pixel on one of the three DMDs. Stuck pixels are almost certainly mechanical defects in the DMD. Given the size of those mirror elements, especially at 4K, a single dust particle is sufficient to cause havoc. I've had some luck with a consumer DLP projector once, where I got all medieval on the light engine. Shaking it around actually revived the stuck pixel. It's not something you want to try on a proper DCI projector though. Maybe TI could implement a function to selectively disable single pixels entirely. This could, maybe, help in a select number off defects, where the pixel isn't completely mechanically stuck in the "on" position.  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 12-01-2014 09:30 PM                     I have just one projector with some stuck green pixels...but I think it is electronic rather than mechanical...the pixels (several) are in a straight line, not random across the raster.  |  IP: Logged Marcel Birgelen Film God Posts: 3357 From: Maastricht, Limburg, Netherlands Registered: Feb 2012 posted 12-02-2014 02:11 AM                     I've seen clusters of four pixels in a square or two or three pixels side-by-side being stuck in always-on positions. There might be quite a lot more stuck in an always-off position, but those are considerably harder to spot in normal production use. They become rather evident on an all-white image though. Those clustered failures are probably due to the same mechanical issue. A row of pixels being stuck indeed sounds more like a problem in the underlying transistor layer. Still probably nothing you will be able to fix by re-seating some boards, unfortunately. Some of those early DLP chips primarily used in rear-projection TVs had this "white-snow" defect, where lots of pixels would become stuck within a rather short timeframe. Due to the single DMD design, the pixels were white rather than one of the primary colors. This was clearly some kind of quality issue with those DLP chips, I haven't seen anything similar with newer DLP engines though.  |  IP: Logged Gavin Lewarne Master Film Handler Posts: 278 From: Plymouth, UK Registered: Aug 2009 posted 12-02-2014 06:09 AM                     my local multiplex has a mix of 2k/4k and on some screens there are some stuck blue pixels. However, my 2 year old 2k Barco at our place has none whatsoever Saying that, I would be interested to hear the Warranty standpoint on this should they ever occur, we are a VPF site  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 12-02-2014 06:27 AM                     If you have stuck pixels...it is a light engine change...so if your projector is in warranty, Barco will consider that a reason for a light engine swap. If it is out of warranty...it is up to you if you want to pay for a new light engine.  |  IP: Logged Marcel Birgelen Film God Posts: 3357 From: Maastricht, Limburg, Netherlands Registered: Feb 2012 posted 12-02-2014 08:56 AM                     Like Steve already mentioned, they're a valid warranty case, at least for professional cinema gear. They're also annoying as hell, especially if it hits multiple pixels or if they're in the center region. Even a single always active or dead pixel should be covered. So while your gear is still under warranty (VPF or not shouldn't matter, as the VPF provider can still file a warranty claim on behalf of their customer) you should regularly check for it. If you're out of warranty on the equipment itself, but still under VPF, it's best to check if your contract states anything about it and who pays for replacement parts and service. Because, indeed, the only way to get rid of it is by replacing the light engine and those things aren't cheap... But, some of those multiplexes care so little about presentation quality, they don't even take the opportunity to get this fixed, even if it's still covered by warranty.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 12-02-2014 12:14 PM                     Fortunately NEC refurbishes their light engines so you are only going to pay about 20% of the cost of a new engine. I have to get the hours on these projectors. One is almost 4 years old... that's the one with 86 stuck blue pixels. The other one is just out of warranty and NEC is considering that one because it's an important "Hollywood Type" location. Mark  |  IP: Logged Ken Lackner Phenomenal Film Handler Posts: 1907 From: Atlanta, GA, USA Registered: Sep 2001 posted 12-02-2014 01:08 PM                     quote: Mark Gulbrandsen the one with 86 stuck blue pixels Did you sit there and count them??  |  IP: Logged Marco Giustini Film God Posts: 2713 From: Reading, UK Registered: Nov 2007 posted 12-02-2014 03:28 PM                     4-5y old Barco 2K, one stuck blue pixel. I've seen a Christie with a stuck blu one, 2y ago. Then I have a Barco with what seems to be the same pixel dead - all three colours! I know, it can't be the DMD. But it is exactly the shape of one pixel, in red and green. Blue is more of a small blotch. I can't think of a place inside the light engine where something like that could happen!  |  IP: Logged Gavin Lewarne Master Film Handler Posts: 278 From: Plymouth, UK Registered: Aug 2009 posted 12-02-2014 04:21 PM                     Marco, could that be caused by a small chip / scratch on the output prism?  |  IP: Logged

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