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Author Topic: Xenon Rectifier Help! Jeff Taylor Jedi Master Film Handler Posts: 601 From: Chatham, NJ/East Hampton, NY Registered: Apr 2000 posted 07-25-2001 11:10 AM                     I need some help from our tech experts on a xenon power supply issue. The machine is an Eiki 1510 16mm unit which has been fine until last night. For background, it's a 300w unit with separate reactance power supply normally drawing 15a @ 22v. My only previous observation was that the amperage tended to drop 25% when the unit got hot, but it was still within the range of the controller. Last night it dropped more than normal, and after 3 hours the lamp wouldn't restrike until cool--all I got was the ignitor "sizzling". Ultimately it restruck, but later would not. I tried a new lamp with the same results. I do have the manual, and suspect either diodes or caps after 25 years, but would VERY MUCH appreciate some practical troubleshooting advice. Also, Eiki no longer supports the machine, so replacement parts will have to be generic, and I would like some thoughts on sources and parts substitution. I can check voltages, but that's about where I run out of knowledge. Thanks!  |  IP: Logged Will Kutler Phenomenal Film Handler Posts: 1506 From: Tucson, AZ, USA Registered: Feb 2001 posted 07-25-2001 03:35 PM                     I ran into a similar problem with the Christie SLC Lamphouse. It turned out that the contactor relay was bad, which also resulted in some fried wiring. Make sure that all of your wiring and connectors are ok--and that connections are secure and that no bare wires are shorting against one another. You can use a v.o.m. (multi meter) to check the diods. Many of these parts may have the component manufacturers name and info on it. Write down whatever info is on the part--and double check the books. Your local electronic store may be able to cross-reference the part numbers.  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 07-25-2001 06:26 PM                     When you are in a situation where there is a major current drop occur over time it is usually cossed by a bad or loose connection wheter it be a contact on the relay or a terminal. A bad contact will have resistance and since ohms law is impartial to where it plays its havoc if there is current flowing and resistance there will be heat. If there is head in a metalic object it will expand and open farther apart or the corrosion will increase the resistance till poof  |  IP: Logged Ken Layton Phenomenal Film Handler Posts: 1452 From: Olympia, Wash. USA Registered: Sep 1999 posted 07-26-2001 06:18 PM                     I agree---check all connections for tightness/cleanliness. The contacts on the line contactor may be getting burned/pitted. My schematic shows a cooling fan is in the circuit. Make sure it's up to snuff and moving air at the proper airflow. The fan isn't clogged with dirt/lint is it?  |  IP: Logged Jeff Taylor Jedi Master Film Handler Posts: 601 From: Chatham, NJ/East Hampton, NY Registered: Apr 2000 posted 07-30-2001 09:06 AM                     Gordon & Ken: I've checked the connections on the board in the projector itself, and also the relay which drops out the high voltage. All seem fine. I'm increasingly convinced it's a diode, but a friend of mine who runs an ABC affiliate TV station volunteered to have his techs fix it. Turns out his transmitter guy has been around long enough that he has a good deal of film chain experience and has done AV repair in the past, so I think he'll be able to handle it. Thanks for all the help.  |  IP: Logged John Anastasio Master Film Handler Posts: 325 From: Trenton, NJ, USA Registered: Sep 2000 posted 07-30-2001 01:29 PM                        Be sure to let us know what he finds. I've got a 1510 also and I might find the info handy some day!  |  IP: Logged Jeff Taylor Jedi Master Film Handler Posts: 601 From: Chatham, NJ/East Hampton, NY Registered: Apr 2000 posted 08-30-2001 02:12 PM                     You guys were great in helping me with suggestions when my Eiki xenon decided to go on strike some weeks ago(or I should say non-strike...it wouldn't!) I was convinced it was a diode or cap problem in the power supply, but couldn't make any progress so I gave it to a buddy of mine who runs a TV station and he had his transmitter tech look at it. Well, I certainly feel stupid not having checked this, but the problem was the rear (negative?) lead on the bakelite plate which contains the focusing mechanism and also mounts the lamp. Apparently the lead had oxidized, virtually burned through, and partially melted the bakelite piece in the process. Apparently it could still pass the high voltage ignition current, but not the amperage required to support the low voltage arc. Anyhow, he's in the process of rebuilding the bakelite assembly as best he can, and I think I have a lead on a new one from a parts machine, so all seems to be going in the right direction. Just thought you'd like to know, and thanks again!  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 08-31-2001 11:25 AM                     Its pretty much my SOP to check all nuts and bolts on brand new rectifiers and then at least every two years in operating theatres. Rectifiers that are VERY PRONE to having high current connections loosening up are Strong, Christie, and Kneisley. Particuluarly KNeisley and Christie as they use a fibreglas or fibre terminal board that connections are made to. These boards compress over the years and loose connections seem to be the result of this. On new stuff it sometimes is not tightened up at the factory or comes loose in shipping. I do the same thing for large dimmer racks as well. Much higher currents are delt with there.....as much as 600 to 1000 amps sometimes is running through the busses. So proper component torque is extremely important in high current situations for reliabilitys sake. Mark @ GTS  |  IP: Logged Jeff Taylor Jedi Master Film Handler Posts: 601 From: Chatham, NJ/East Hampton, NY Registered: Apr 2000 posted 09-02-2001 05:51 PM                     Mark: I almost hesitated to post my happy news given how stupid I felt missing that issue. We typically spend $10,000 or more annually in large commercial buildings having switchgear infrared tested and the busses cleaned and tighened, so i should have thought about it here. Guess I just heard too much talk about diodes going south and assumed the first possible cause. Anyhow, I did find an "intact" bakelite part from a good samaritan with a parts machine, and it's on its way "as we speak". Guess all's well that ends well.  |  IP: Logged Bruce McGee Phenomenal Film Handler Posts: 1776 From: Asheville, NC USA... Nowhere in Particular. Registered: Aug 1999 posted 09-03-2001 01:25 PM                     Jeff: Would this parts machine be one that I used to know? If it is, I am thrilled that you guys are getting some good out of it. Bruce  |  IP: Logged Jeff Taylor Jedi Master Film Handler Posts: 601 From: Chatham, NJ/East Hampton, NY Registered: Apr 2000 posted 09-04-2001 07:52 AM                     Bruce: Yep...none other than the machine you "used to know". If you recall I put the fellow on to it when you mentioned it was available. It's come in very handy--this is not the first part I've gotten from it, including the "impossible to find" jack for the solar cell lead so I didn't have to do any cutting to run the sound directly to my rack.  |  IP: Logged Gerard S. Cohen Jedi Master Film Handler Posts: 975 From: Forest Hills, NY, USA Registered: Sep 2001 posted 09-08-2001 01:40 PM                     Jeff Taylor-- I had the same problem with sickening current dropoff feeding a XeTron lamphouse with 3,oooW lamp. Fortunately wisps of smoke and heat showed location of the problem. A hole was burned through the bakelite plate, the outer lamp-feeding cable and inner multiple wires from the rectifier coils and switches were badly charred and brittle. The headless bolt that connected them all was hot as hell. I trimmed the burned cable and wires, affixed new lugs, and replaced the brass bolt with a shorter bronze bolt, and left it hanging in the hole. (I suspected the discarded bolt was made of metal with too high resistance, as its color was different from the one with the opposite polarity, which always remained cool.)Since then I learned to tighten all connections regularly Appeal to the U.A. service department for a new bakelite plate was answered about a year later, but their service tech never bothered to install it, and it remained in the parts cabinet until the theatre was closed.  |  IP: Logged

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