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Author Topic: Any problems with OSRAM "Classic" bulbs? Jon P. Inghram Expert Film Handler Posts: 124 From: Wichita, KS USA Registered: Jan 2007 posted 06-21-2008 12:28 PM                     Anyone has any problems with these? We just replaced a XBO 4000W/HS CL OFR after only 1318 hours because the arc was unstable and off-center and the anode end of the bulb was developing an disturbing looking blotchy blackening, not just the regular over-all darkening that an old bulb develops. The last two bulbs (both "regular" XBO 4000W/HS OFRs) ran for 6882 and 4716 hours in that particular lamphouse, a Big Sky.  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 06-21-2008 03:30 PM                        You've answered your own question: 2 are good, one is bad. It is always possible to get a random bad bulb, especially if seal damage is the culprit. Louis  |  IP: Logged Tim Reed Better Projection Pays Posts: 5246 From: Northampton, PA Registered: Sep 1999 posted 06-21-2008 05:23 PM                       How many hours are 4000 HS's warrantied for?  |  IP: Logged Troy Hilsman Powell Film Handler Posts: 30 From: Jacksonville,FL Registered: May 2007 posted 06-21-2008 05:47 PM                     Sounds like low gas pressure in the bulb but you better check your air cool flow on the bulb.  |  IP: Logged Jon P. Inghram Expert Film Handler Posts: 124 From: Wichita, KS USA Registered: Jan 2007 posted 06-21-2008 07:58 PM                     The normal and "Classic Line" models are now 1000 hours, the "Xtreme Life" model is 1500. I think they used to be rated at 2000 hours, but I might be wrong on that. The lamphouse airflow is good. The replacement bulb is a XL model, but (hopefully) we'll have new projectors before we find out if it actually lasts any longer.  |  IP: Logged Tim Reed Better Projection Pays Posts: 5246 From: Northampton, PA Registered: Sep 1999 posted 06-21-2008 11:46 PM                       I remember them being warrantied anywhere from 800-1200 hours years ago. I was just wondering if something had changed dramatically recently. 6800 hours is pushing it.  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 06-22-2008 12:12 AM                     Dang, how did the light output look like with 6800 hrs on a bulb with an 800 hr warranty? Some serious hours there when it should have been pulled around 2000hrs..  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 06-22-2008 10:10 AM                     Actually the Redwood Drive in SLC that also utiizes those nifty Canadian reflector conversons typically gets 3,000 hours out of their Osram 4kw's, they also come out more or less clear. The result of using hurricane blowers. The blotchy black is due to the fact that today's lamps have a "getter" in them. This "getter" attracts the spent tungsten that is vaporized during lamp operation. So a little blotchy black is perfectly acceptable although indicative of lots of lamp hours and possibly not enough lamp cooling. Back when lamps did not have those "getters" in them lamps more or less turned black evenly on the inside creating a dangerous situation where internal heat could not escape fast enough. Mark  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 06-22-2008 01:08 PM                     what about quartz derivication (excuse the spelling) when quartz gets the hours on it?  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 06-22-2008 03:31 PM                     Thats hard to say Monte... I'm hardly a glass expert but typically when a lamp explodes from high hours its no doubt due in part due to vitrification of the glass. Considering that we havae customers that run CXL20 and 20R lamps well past 20K hours its certainly a non issue until the lamp reaches extremely high hours. What I typically see on the 20's at those high hours is that the lamp is finally unstable... amazingly, the envelopes are still clear. Mark  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 06-23-2008 12:27 AM                     quote: Mark Gulbrandsen amazingly, the envelopes are still clear. ..which I've also experienced with 20R bulbs with over 7k hours on a few occasions - but new better of the needed changeout in case one does let go in our X90's and I'd have to give a fully detailed explanation on why I let a bulb stay in a console too long ... and obviously I don't want to be engaged in that war-a war that I'd win that battle in defense, but still lose the war in the long run. -Monte  |  IP: Logged Jon P. Inghram Expert Film Handler Posts: 124 From: Wichita, KS USA Registered: Jan 2007 posted 06-23-2008 12:27 PM                     The bulb that hit 6882 hours was replaced because it was flickering. The bulbs have averaged 4383 hours, and were replaced half the time because they started to flicker, and the other half because they were getting dim.  |  IP: Logged Jon P. Inghram Expert Film Handler Posts: 124 From: Wichita, KS USA Registered: Jan 2007 posted 11-01-2008 01:50 PM                     Had another 4k OSRAM Classic bulb kick the bucket at only 1005 hours. It had been running perfectly, but when I went to start it this morning the arc spread across the entire inside of the bulb and was very, very dim. My guess was that it developed a leak, which was confirmed when we pulled it out: It looked like blue frosted glass on the inside of the bulb.  |  IP: Logged Mike Olpin Chop Chop! Posts: 1852 From: Dallas, TX Registered: Jan 2002 posted 11-01-2008 02:07 PM                     A bit off topic - I love it when I find a strange lamphouse that for whatever reason allows ungodly long bulb life. #3 at Rancho San Diego (Christie SLC, CXL-40) was like that. The image stayed perfectly steady and bright after 2-3000 hours! I never had to pull a bulb out of it due to flickering or brightness, always pulled bulbs due to age, nothing else. By far the brightest and sharpest machine in that complex. What weird voodoo causes this? I didn't treat it any differently than the others.  |  IP: Logged Tony Bandiera Jr Film God Posts: 3067 From: Moreland Idaho Registered: Apr 2004 posted 11-01-2008 02:38 PM                     At one major art house chain here in L.A. the chief projectionist had discovered that he could get much extended bulb life by killing the LAMPHOUSE blowers immediately at show end, leaving the stack exhaust running. (I should mention that unlike the majority of installations I have run across, all his theatre's stacks had at LEAST 550cfm measured at the lamphouse.) Prior to doing this, he would average just above warranty life on the bulbs (virtually all were Osram 4k), after changing the lamphouse wiring to kill the blowers on shutdown, bulb life was well over 5k-6k hours each. Lamphouses are LP Associates 8540s. quote: Monte L Fullmer Dang, how did the light output look like with 6800 hrs on a bulb with an 800 hr warranty? Some serious hours there when it should have been pulled around 2000hrs Monte, when I started in this business back in '82 I was of the "pull the bulb at warranty hours" school. But since then, not only have bulb technologies improved, but user experience has shown that is is far wiser to only change bulbs if they are hard to start, flicker or have excessive darkening of the envelope. Over literally hundreds of screens and many years that I have been around, I can count on one hand the number of bulb explosions. Better to leave a sleeping dog lie, or in this case, a working bulb alone.  |  IP: Logged

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