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Author Topic: Christie CP2220 red/green blemishes Christian Hove Film Handler Posts: 41 From: Aalborg, Aalborg, Denmark Registered: Jan 2012 posted 10-31-2016 07:46 AM                     One one of our CP2220s we are experiencing static red/green colored blemishes near the center of the image. The blemishes are pink on white test pattern and green on black image. Changing the lamp does not solve the problem. White test pattern: Black: Anyone got a clue what is going on? I've made the original pictures avaliable here: https://www.dropbox.com/sh/uswksfsosacdnr9/AADiqU9B7NPhYZ998usCR_uha?dl=0 In the shared dropbox folder, there is also a video recorded during lamp alignment - The video shows that the shape and intensity of the blemished changes with the lamp position in the mirror. Thanks, Christian  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 10-31-2016 10:12 AM                     Generally, when you have colored blemishes, that indicates an obstruction on one or more of the colors. When you put up just green do you find that blemishes are where the magenta ones were but now they appear "black?" That would indicate that those parts of the green imager are being obstructed (dirt).  |  IP: Logged Carsten Kurz Film God Posts: 4340 From: Cologne, NRW, Germany Registered: Aug 2009 posted 10-31-2016 02:59 PM                     I'd say, call a tech in for cleaning. - Carsten  |  IP: Logged Marco Giustini Film God Posts: 2713 From: Reading, UK Registered: Nov 2007 posted 10-31-2016 03:41 PM                     Are there techs (besides Mark) who can clean the engine one site?  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 10-31-2016 04:52 PM                     I think it depends on the projector as to what one can do, on site. NEC is the most open and affords one the best chance at cleaning (then again, it s more likely to get dirty too).  |  IP: Logged Christian Hove Film Handler Posts: 41 From: Aalborg, Aalborg, Denmark Registered: Jan 2012 posted 11-01-2016 06:53 AM                     Thank you all for your replies. Yes Steve, with green test image, the blemishes turn black:  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 11-01-2016 05:16 PM                     Well there you have it...you have dust/dirt on your green imager...that is what needs to be cleaned/blown out. -Steve  |  IP: Logged Rex Oliver Film Handler Posts: 65 From: Greenville, NC. USA Registered: Apr 2013 posted 11-02-2016 01:40 AM                     Looking at these problems--so reminds me of doing color purity adjustments on old RCA color TV's!  |  IP: Logged Christian Hove Film Handler Posts: 41 From: Aalborg, Aalborg, Denmark Registered: Jan 2012 posted 12-13-2016 08:39 AM                     Just an update: The blemishes has disappeared by themselves without any cleaning - I am happy but somewhat mystified...  |  IP: Logged Dave Macaulay Film God Posts: 2321 From: Toronto, Canada Registered: Apr 2001 posted 12-13-2016 09:06 AM                     The light engine has air blown across the DMDs by the "LAD Fan" (Laminar Air Devices?) which should keep dust from sticking on the DMD and prism faces. I would want to open the top and check there's no water ingress or coolant leaks.  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 12-13-2016 09:33 AM                     I'm with Dave on this one.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 12-14-2016 10:15 AM                     I'm not a real fan of the laminar air flow system in those to be honest. The filters in the projector are not capable of keeping out moisture or popcorn oil. Mark  |  IP: Logged Marco Giustini Film God Posts: 2713 From: Reading, UK Registered: Nov 2007 posted 12-14-2016 03:32 PM                     neither am I. Some minute dust will eventually build up, killing contrast. Unless there is a way to clean that path I rather have a sealed engine. If your engine requires cleaning, I am told BTW that Christie in some countries are not honouring the warranty for projectors which are NOT operated in filtered-air environments - can anybody confirm?  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 12-14-2016 08:07 PM                     Yes, exactly! I can see it might help cool the face of the DMD if you are running large lamps, other than that it's a marketing gimmick. Not sure about booths having to have filtered air. Most do, but only to a minor extent. Filtering air really well in a giant space is very costly. Mark  |  IP: Logged Marco Giustini Film God Posts: 2713 From: Reading, UK Registered: Nov 2007 posted 12-15-2016 12:41 AM                     Christie clearly claimed that the LAD is not for cooling the chips, only for keeping them clean.  |  IP: Logged

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