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Author Topic: Pre-Show Projector Bulb Life Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 08-23-2007 06:34 PM                     Most of the theaters I service get pretty good lamp life but most of the projectors are Sanyo or Panasonic, the latter has always had the best lamp life. Two things to lead to longer lamp life are... 1. Make sure the fan is on high. 2. Make sure the fan stays on after the lamp is switched off. This is not possible on all projectors via automation so it may have to be switched off manually. Mark  |  IP: Logged Andy Muirhead Master Film Handler Posts: 323 From: Galashiels, Scotland Registered: Dec 2000 posted 08-23-2007 06:47 PM                     quote: Mark Gulbrandsen 1. Make sure the fan is on high. I always wondered if setting the fan on my home DLP to the high altitude/fastest/noisest setting would help the lamp life longevity.  |  IP: Logged Jon Miller Jedi Master Film Handler Posts: 973 From: San Diego, CA, USA Registered: Sep 1999 posted 08-23-2007 08:30 PM                     The kind of failure shown in Josh's pictures happens to OEM lamps, too. I am responsible for the lamps in about 100 Epson and Sanyo projectors installed in classrooms and lecture halls at a local university and, while I've found most of the time the lamps go dim from a white deposit on the bulb envelope (devitrification, perhaps?) as the lamp nears the end of its life, once in a while a lamp will suffer from abnormal swelling of the envelope. My gripe with these lamps is that they are not marked with serial numbers -- like xenons -- or, AFAIK, production date codes. A number of years ago we had several lamps from different sources for the same projector model explode with low hours; there was no way to determine whether it was a bad run or just bad luck. Something as simple as a production code stamped on the back of the reflector would make it easy to determine whether repeated failures are projector-related or lamp-related.  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 08-23-2007 08:58 PM                     The NEC factory rep told us that the lamps have a finite shelf life after manufacture and that they tend to degas or leak and get contamination in them over time  |  IP: Logged Darryl Spicer Film God Posts: 3250 From: Lexington, KY, USA Registered: Dec 2000 posted 08-24-2007 04:08 AM                    quote: Thomas Pitt Most digital video projectors have an in-built circuit that keeps the fan going for a while after you press the power button, only turning it off after a time delay or when a temperature sensor triggers it. Would it be possible to somehow set up the automation so that it presses the 'standby' button on the projector, instead of just cutting power? Our Pre-show projectors do have the circuitry but I have found that the fan blows for only two minutes after the bulb shuts off. I think the fans should blow longer than that to adequately cool the lamp. We also use the Christie LW25's.  |  IP: Logged Josh Rosen Film Handler Posts: 49 From: Toronto, Ontario, Canda Registered: May 2007 posted 08-24-2007 10:34 AM                    I have noticed the same thing Daryl. The fans don't blow for very long, and considering the say to wait 45 minutes before changing a bulb for adequate cooling to have occurred, I think the fan should be on longer. Is there any way to tweak this?  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 08-24-2007 10:46 AM                     On the Christie LW25 which is the Sanyo PLV-70, one has to enter the service menu to alter the fan duration or speed. The fan duration is in Group 40, Item 3 The duration ranges from 0 = Always run the fan to "15" which runs the fan for 7-1/2 minutes for cool down. The factory default is "3" which is 90-seconds. How do you get into the Service Menu? Hit the "MENU" and "IMAGE" buttons together for more than 3 seconds. Once in, the Menu button will get you to the group number, the Item number is selected via the Up/Down buttons and the values (data) is selected with the volume's up/down buttons. To get out of the service menu, hit the power button (once to keep the projector on). Now in the service menu you have the great opportunity to screw the projector up so enter at your own risk and only if you are so authorized. As to the fan speed...Group 40, Item 4 sets that..."0" is supposed to be normal with "1" being hi-speed. Steve  |  IP: Logged Bastiaan Fleerkate Film Handler Posts: 85 From: Linschoten, Utrecht, The Netherlands Registered: Jun 2006 posted 08-24-2007 12:48 PM                        I had this same problem with our Panasonic PT-D7600 projector. In my case the bulb would explode when reaching the end of his life at 400(!) hours... The reason was simple... We always turned the the projector off when we started the movie (with the controls on the projector and sufficient cooling time) and turned it on when the intermission started... this caused the lamps to explode in 400 hours. The lamps are weakened by turning them on and off, just like your xenon bulb in your 35mm projector. Now we just use the shutter when we don't need the projector and now we have an avarage lamp-life of 1500(!) hours... Just remember that every time you turn your projector on, you're shortening the life-span of your bulb (in my case bulbs)... Bastiaan  |  IP: Logged Josh Rosen Film Handler Posts: 49 From: Toronto, Ontario, Canda Registered: May 2007 posted 08-24-2007 02:51 PM                    I think the fan might be the best option for us. We use the Kodak digital Cinema pre-show system so the lamp shuts down automatically when the 35mm projector lamp ignites. We don't have much control over the system to change settings like that, but I will definitely look into keeping the fan on longer, thanks for the tip.  |  IP: Logged Thomas Pitt Master Film Handler Posts: 266 From: Leeds, West Yorkshire, UK Registered: May 2007 posted 08-24-2007 03:34 PM                     This probably isn't possible with digital projectors, but I might as well ask - how about dimming the projector lamp (but not switching it off) when it's not in use? This would allow it to cool down a bit, and it wouldn't have to re-strike when you need it again. Of course, you'd probably need some shutter to block the dimmed light, but it might help the overall bulb life! Speaking of dimming, I used to use digital data projectors for presentations. Most of those required at least 30 seconds for the lamp to 'warm up' before the picture was bright enough, but modern projectors tend to come on instantly. Different bulb type, perhaps? With the 35mm slide projectors I mentioned earlier, I've seen a system where the lamp is connected to a separate power supply than the main projector. The lamp dims slowly to off, the slide carousel advances, then the lamp fades up slowly again. I'm not sure, but I think the carousel keeps going round after bulb power has been cut (during the movie). Would this extend or reduce bulb life?  |  IP: Logged Bastiaan Fleerkate Film Handler Posts: 85 From: Linschoten, Utrecht, The Netherlands Registered: Jun 2006 posted 08-24-2007 03:42 PM                        When using the shutter on the digital projector, the lamp automaticaly dims (I thought this is the case with our Panasonic projector). Else you would burn and damage your shutter within minutes...  |  IP: Logged Josh Rosen Film Handler Posts: 49 From: Toronto, Ontario, Canda Registered: May 2007 posted 08-24-2007 05:53 PM                    quote: Thomas Pitt Speaking of dimming, I used to use digital data projectors for presentations. Most of those required at least 30 seconds for the lamp to 'warm up' before the picture was bright enough, but modern projectors tend to come on instantly. Different bulb type, perhaps? Even though the lamp strikes right away, it does usually take 20 - 30 seconds for the picture on-screen to reach its full brightness. Our digital projectors strike the bulbs about a minute before the content is scheduled to start showing, in order to let the bulb read its full brightness.  |  IP: Logged Phil Blake Jedi Master Film Handler Posts: 558 From: esperance western australia Registered: Nov 2003 posted 08-25-2007 12:32 AM                        We have our automation set the same Josh, it strikes the lamp 60 seconds prior to start. I changed the first lamp in my Panasonic 3000 at 250hrs , the lamp was working fine then it just exploded . The replacement has now done 380hours so I am not sure what to expect. We recently added a Panasonic 5000 to the collection , I have experienced very bad lamp flicker on both lamps (dual lamp set up) both lamps had less than 40 hours on them. The flicker was intermittent for about a week then I stopped.  |  IP: Logged Tim Lewis Film Handler Posts: 12 From: Okatie, SC, US Registered: Dec 2006 posted 09-11-2007 09:04 AM                     i've recently had the same problem with my Mitsubishi WD2000's. a possible reason for my problems was that the exhaust fan on that unit is on the front, and the hot air leaving the projector was basically escaping towards the port glass and just sitting there, keeping the front of the projector pretty warm nearly all the time. so we came up with the idea of running a 4" hose (kinda like the exhaust hose on a clothes dryer) from the 35mm projector's exhaust over to the digital. we've just done this, so i can't testify to it's effectiveness in extending lamp life, but it's definately sucking away all the hot air from around the projector. if your digital exhaust vent is within 6-12 inches of the port glass or any other surface, that could be affecting it.  |  IP: Logged Tony Ratcliff Expert Film Handler Posts: 216 From: Madison, IN, USA Registered: Mar 2002 posted 09-11-2007 04:27 PM                     My Sanyo's first bulb only lasted a few months. Near the end the unit kept overheating and shutting down. The main cooling/exhaust fan is on the bottom. So I put it up on blocks to get it 3-4 inches in the air, and also if I need to run it for an extended period of time, I set a small desktop size fan blowing on it to help keep it cool. This second bulb has lasted a lot longer by doing this. I read the newer models of Sanyo's have better cooling, but I can't afford to upgrade right now. So I do what I gotta do.  |  IP: Logged

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