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Author Topic: Christie CH 10 DC switch, NEED HELP Ben Mozer Film Handler Posts: 12 From: Fort Collins, CO Registered: Oct 2005 posted 10-27-2010 02:33 PM                     I had the DC connector in the rectifier short out last night. The AC wire seemed to have come into contact with one of the heat sinks, which caused the short, so the connector makes a loud buzzing sound when the manual DC switch is thrown. I replaced the connector in the rectifier, but it still doesn't work and still makes the loud buzzing sound. I am, admittedly, an amateur at this, so I don't know what to look for next and my repair man can't get here for a couple days.  |  IP: Logged Ben Mozer Film Handler Posts: 12 From: Fort Collins, CO Registered: Oct 2005 posted 10-27-2010 04:31 PM                     Seriously though, I really really need some help. If I'm asking in the wrong way or not giving enough info, let me know and I will correct it.  |  IP: Logged Richard May Phenomenal Film Handler Posts: 1057 From: Floral Park, NY USA Registered: Aug 2004 posted 10-27-2010 05:05 PM                     I think it's just confusing that the connector is making noise. Could the noise just be coming from somewhere in the rectifier that you can't pinpoint? Sounds like it may be a shorted diode.  |  IP: Logged Ben Mozer Film Handler Posts: 12 From: Fort Collins, CO Registered: Oct 2005 posted 10-27-2010 05:09 PM                     It may be from something else, but it sure seems like it's coming from the DC connector. When I flip the manual switch to strike the lamp, that's when it starts buzzing. When I take the panels off the listen for the noise, it sounds like it's coming straight from that connector. Also, it may be a diode because the insulation on the AC wire was burn through and actually making contact with the heat sink. But, if it's a diode, why does it sound like the connector is buzzing? Do I need to replace the diodes or the entire heat sink? Could there be more shorted out than just that? L ike I say, I'm no expert on this by any stretch of the imagination.  |  IP: Logged Richard May Phenomenal Film Handler Posts: 1057 From: Floral Park, NY USA Registered: Aug 2004 posted 10-27-2010 05:17 PM                     Did it happen in the middle of the show or at start up? Exactly what happened?  |  IP: Logged Ben Mozer Film Handler Posts: 12 From: Fort Collins, CO Registered: Oct 2005 posted 10-27-2010 05:19 PM                     It happened last night when I wasn't here. But, from what I can tell, it happened right at the start of a show. I'm guessing that the wire was laying on the heat sink for a while and the insulation finally melted through at the beginning of that show. I think I'm mostly afraid that I have to replace the entire rectifier now....that would be pretty pricey.  |  IP: Logged Richard May Phenomenal Film Handler Posts: 1057 From: Floral Park, NY USA Registered: Aug 2004 posted 10-27-2010 05:22 PM                     Usually when a diode shorts, it trips the breaker. Sometimes, especially with Christie rectifiers, it doesn't trip the breaker and makes this low pitched LOUD hum or buzz. It could be a shorted diode that didn't trip the breaker and overheated the AC wire.  |  IP: Logged Ben Mozer Film Handler Posts: 12 From: Fort Collins, CO Registered: Oct 2005 posted 10-27-2010 05:25 PM                     I've had to replace diodes before, and this didn't seem like a diode problem to me. But I might replace those for good measure (hopefully I have a positive AND negative) and replace that wire as well.  |  IP: Logged Richard May Phenomenal Film Handler Posts: 1057 From: Floral Park, NY USA Registered: Aug 2004 posted 10-27-2010 05:27 PM                     Test them all first to see. From what you're telling me, it sounds like it.  |  IP: Logged Jeremy Weigel Phenomenal Film Handler Posts: 1062 From: Edmond, OK, USA Registered: Mar 2007 posted 10-27-2010 05:33 PM                     Just to be certain, you're not talking about a contact relay that's making a buzzing sound?  |  IP: Logged Ben Mozer Film Handler Posts: 12 From: Fort Collins, CO Registered: Oct 2005 posted 10-27-2010 05:38 PM                     Yeah, I think that's what it is (I don't know all the jargon yet). It's the mechanism that flips in the rectifier when you turn the Manual DC on. And what, exactly, do I touch with the voltmeter to test each diode?  |  IP: Logged Richard May Phenomenal Film Handler Posts: 1057 From: Floral Park, NY USA Registered: Aug 2004 posted 10-27-2010 05:46 PM                     Even so, I still think it may be a diode. I don't know what would buzz on the contactor. With an ohm meter you check each diode one by one. Take it off the heat sink. Put one lead on the threads and the other lead on the stem. Then switch leads. If it's "closed" in both directions, it's shorted.  |  IP: Logged Jeremy Weigel Phenomenal Film Handler Posts: 1062 From: Edmond, OK, USA Registered: Mar 2007 posted 10-27-2010 05:53 PM                     I've had contactors that have gotten weak and will buzz. Usually you can lightly tap on the top of it and it will finish pulling down the contacts or on some you can actually push the contact bar down.  |  IP: Logged Richard May Phenomenal Film Handler Posts: 1057 From: Floral Park, NY USA Registered: Aug 2004 posted 10-27-2010 05:58 PM                     He said he replaced it with another one though.  |  IP: Logged Ben Mozer Film Handler Posts: 12 From: Fort Collins, CO Registered: Oct 2005 posted 10-27-2010 06:00 PM                     Yeah, I replaced the contactor. The old one was OBVIOUSLY burnt out. But the same problem persists and the lamp won't ignite.  |  IP: Logged

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