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Author Topic: Picture flicker on Christies Eric Robinson Jedi Master Film Handler Posts: 538 From: Santa Rosa, CA Registered: Jan 2005 posted 03-30-2007 10:58 AM                     I was going to suggest rotating the shutter blade out of the light path manually. Shine the light on the screen without the motor running for a brief period of time so that you don't burn the lens. If you see flicker, its from your light source. Also, since you removed the diode assembly, this would be a perfect time to order new diodes and rebuild it for future use. I keep 2 or 3 spares sitting around for quick swap outs.  |  IP: Logged Frank Dubrois Jedi Master Film Handler Posts: 896 From: Cleveland, OH Registered: Mar 2005 posted 03-30-2007 11:04 AM                    quote: Demetris Thoupis If the flicker is visible go straight on the lamphouse/rectifier. What does that mean? The flicker is visible without film running.  |  IP: Logged Sean McKinnon Phenomenal Film Handler Posts: 1712 From: Peabody Massachusetts Registered: Sep 2000 posted 03-30-2007 08:33 PM                        I believe that if you had a shorted diode and looked at the light through an open shutter you would not see and "flicker". The "Flicker" comes from the 60 cycle A/C that the shorted diode is allowing across the bulb interacting with the 48 cycle shutter blade. Looking at it through an open shutter would be no different than looking at the light from an incandessant lamp, no visible flicker. You need the 48 cycle shutter to see the effect.  |  IP: Logged Frank Dubrois Jedi Master Film Handler Posts: 896 From: Cleveland, OH Registered: Mar 2005 posted 03-30-2007 09:30 PM                    So other than swapping out the diodes...I have no clue as to what this could be.  |  IP: Logged Alex Grueneberg Expert Film Handler Posts: 125 From: Chicago, IL Registered: Aug 2004 posted 03-31-2007 12:27 AM                        Frank, as I believe we seem to be having similar issues I'd go with diodes for sure. I swapped out another larger flickering house (4k) yesterday night and Meet the Robinsons just for regular old 35 looks pretty darn spiffy. And now I don't get headaches from #4! Hell, your only in Ohio. Mind if I stop by to catch a flick?  |  IP: Logged Frank Dubrois Jedi Master Film Handler Posts: 896 From: Cleveland, OH Registered: Mar 2005 posted 03-31-2007 01:29 AM                    Sure come on by...replace my diodes and stay for a flick  |  IP: Logged Demetris Thoupis Phenomenal Film Handler Posts: 1240 From: Aradippou, Larnaca, Cyprus Registered: Apr 2001 posted 03-31-2007 03:20 AM                     quote: quote: Demetris Thoupis If the flicker is visible go straight on the lamphouse/rectifier. What does that mean? The flicker is visible without film running. Start The Projector With NO FILM. Shine the lamphouse If flickering then probably is lamphouse [ 03-31-2007, 12:20 PM: Message edited by: Adam Martin ]  |  IP: Logged Frank Dubrois Jedi Master Film Handler Posts: 896 From: Cleveland, OH Registered: Mar 2005 posted 04-02-2007 12:08 AM                    When people say they have a spare diode rack sitting around to pop in in case of emergencies, how long does it take you? Where do you disconnect the wires? at the diode? Do you have to then label your wires to reconnect? curious.....cuz it sounds like a very easy way to replace all 6 diodes..in the light...at my leisure.  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 04-02-2007 02:24 AM                     If you got a CHR-SLC manual (or have these consoles..), look at pg A-15 in the parts section and you can see the bank that holds these diodes. They're not too hard to work on (if you know what you're doing), just to ensure that you make sure that you have the correct polarity diodes per each side of the bank and ensure that connections are very tight. (I still think the bulb is too far into the mirror causing a very slendor cone of light - why of your original complaint on the flicker...)  |  IP: Logged Frank Dubrois Jedi Master Film Handler Posts: 896 From: Cleveland, OH Registered: Mar 2005 posted 04-02-2007 02:37 AM                    Nope..I checked that. The only thing left is diodes (that I know of). Thats why having a spare rack would be nice. When one goes out, simply replacing the rack instead of on my knees digging around inside the lamphouse and busting knuckles. I like the rack swap idea very much. Any idea on what a bare rack without diodes runs?  |  IP: Logged Alex Grueneberg Expert Film Handler Posts: 125 From: Chicago, IL Registered: Aug 2004 posted 04-02-2007 03:22 AM                        I had to replace them individually on one unit. Personally, I disconnected the wires from the junction (where they each meet) and removed the entire heat sink with diodes and all. It's MUCH easier to work on. I'm a much more visual person so maybe I'll snap a pic tomorrow for a better explanation. And as Monte said, the manual does help.  |  IP: Logged Frank Dubrois Jedi Master Film Handler Posts: 896 From: Cleveland, OH Registered: Mar 2005 posted 04-02-2007 03:10 PM                    I've got a manual, but I was just wondering where you disconnected the rack at...at the diodes or at the other end. A picture would be great. Thanks!  |  IP: Logged Phil Ranucci Expert Film Handler Posts: 236 From: Carpinteria,CA, United States Registered: May 2006 posted 04-02-2007 03:26 PM                     Disconnect at the other end, leave the tails on the diodes. This will make it easier to find the bad one(s).Undo the leads to the lamphouse and pull the entire rack out. Then you can work on a bench with plenty of light.Don't forget the heatsink compound.We have spare racks, it makes life much easier. However,if you get one, make sure that it will fit all of your machines, as they differ due to era and capacity.  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 04-02-2007 10:35 PM                     ..and on a small side note while you have your head buried in that console pulling that diode bank out: On the three-phase, 18 position rotary tap switch, look behind that switch and take a small socket wrench and double chek those nuts that are holding down the wires to that rotor switch plate, for if you have a couple of loose wirenuts there, that rotor switch will go 'kapooie' on you without you knowing about it..(and you wonder why your light output goes real dark all of a sudden..HMMMMM....have you checked this area out some per chance on this flickering issue, per any chance? You could have a winding leg not making the best contact in the world back there....) good luck, once again - MONTE  |  IP: Logged Phil Ranucci Expert Film Handler Posts: 236 From: Carpinteria,CA, United States Registered: May 2006 posted 04-02-2007 11:55 PM                     .and on a small side note while you have your head buried in that console pulling that diode bank out: On the three-phase, 18 position rotary tap switch, look behind that switch and take a small socket wrench and double chek those nuts that are holding down the wires to that rotor switch plate, for if you have a couple of loose wirenuts there, that rotor switch will go 'kapooie' on you without you knowing about it..(and you wonder why your light output goes real dark all of a sudden..HMMMMM....have you checked this area out some per chance on this flickering issue, per any chance? You could have a winding leg not making the best contact in the world back there....) good luck, once again - MONTE OH YEAH, forgot about that. We had that happen on a Sunday evening, the other tech changed diodes but never saw the 1" hole burned through the tap switch. Be aware that the ones you get from Christie now have much larger posts on them, which is good from a reliability standpoint, but bad from a service standpoint since none of the wires will fit and you'll have to put new terminals on all the wiring. We had some old ones that we swapped in. You might get lucky and go to a different tap setting that will give acceptable light until you can get a new switch. When people say they have a spare diode rack sitting around to pop in in case of emergencies, how long does it take you? Where do you disconnect the wires? at the diode? Do you have to then label your wires to reconnect? curious.....cuz it sounds like a very easy way to replace all 6 diodes..in the light...at my leisure. You disconnect the wires where they attach to the terminal board above the diode stack, undo the output leads, unbolt the stack and put the new one in.Takes about 20min. You can label the wires but they really just fall into place and it's easier than it sounds. The stacks are different,or at least ours are, in different models. We have 2K&3K stacks with wire leads off the diodes and a 4K with copper buss bars.  |  IP: Logged

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