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Author Topic: Failures Of Kelmar LED-Scanner Supplies Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 01-25-2006 09:28 PM                     Over the the last year we had close to a dozen of the beige/gray color supplies fail. Another one yesterday! All were on the order of 6 to 7 years old. Typically they fail at the dam Molex connector but I have also seen traaces and components behind that Molex burn up as well. The bizzare thing is that this is all low voltage and current stuff and a Molex shouldn't be failing at all. Anyone else experiencing this problem? We have been replacing them with the small CE power supply as its alot less expensive and seems to be built better...... Its certainly alot more repairable! Mark  |  IP: Logged Mike Babb Master Film Handler Posts: 250 From: Norwich UK Registered: Jul 2002 posted 01-26-2006 05:16 AM                        I have replaced a half dozen of these over the past couple years and I think my boss has done about the same amount. A couple were in the black boxes too, not just the older grey ones. I think the fact that most of our houses are running digital masks the problem.  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 01-26-2006 12:55 PM                        Mark, the initial Kelmar supplies were capable of operating at up to an amp on the LED. Originally we were told these were "preset". Later we changed the output resistor to a higher resistance so we could get the LED current down to 225 ma or less. I have seen 1 or 2 of the grey boxes with this problem. Usually we change the lens (on analog) along with either the box or the resistor. Changing the box is no longer an option since it is no longer available. The new analog Kelmar black box is significantly better than what you saw in the past; complete redesign....courtesy of Thomas Mohr. Let's not even speak about the older CE power supplies....Purdy era. Louis  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 01-26-2006 07:19 PM                     Louis, I agree... Some of the early CE stuff was Purdy bad..... I have been using the LS-40 power supply if we don't just yank it all out and do a BACP. The LS-40 has a list of $120, pretty hard to beat its bang for the buck. It has several advantages over Kelmars new design and is built alot better. Nothing against Thomas though... we use lots of his stuff. Mark  |  IP: Logged Sam D. Chavez Film God Posts: 2153 From: Martinez, CA USA Registered: Aug 2003 posted 01-26-2006 07:22 PM                       Louis, I can't have you trashing Bill Purdy like this. That's my job! Kidding! The fine memories of going to the first installation and finding an audible 400 hz note coming from the LED. That turned out to be only the begining of trouble. I had a heart attack not too long after. I do use the current version CE power supply with my DP75 readers with great results.  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 01-26-2006 08:22 PM                     The LS-20 supplies definately had issues...you could tune that tone by breaking the inductors and moving the coils around... The LS-30 is a great supply and the LS-40 is very good too, though I like the LS-30 better. I haven't cared for any of the Kelmar supplies, including the Black one...poor current range and even oscillations with the thing...I'll stick with CE for such things.  |  IP: Logged

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