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Nycon
Joined: 10 Apr 2007 Posts: 34 Location: Germany, NRW
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Link Posted: Thu Jan 08, 2015 8:50 pm Post subject: Marquee 9500 - Tubes shutting down & refocussing, repeat |
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Hi everyone,
after quite a few years of use I have run into a problem with my Marquee 9500 LC Ultra. A while back I had the problem that the image was flickering slightly, basically turning off for the duration of one or several frames. Checked cable connections back then and everything seemed to be fine but Problem persisted. Removed HV and LV power supply, cleaned contacts and removed dust (not much in there anyways), unplugged and reconnected all connections at the HV ditributor (grey box with input from HV supply and output to all three tubes). Issues were solved, that was about two months (~40hrs of use) ago.
A few days ago I had a problem with the tubes shutting down completely for a few seconds, then projecting an image again which went from completely unfocussed to normally focussed, staying stable for a second or two, and then shutting down again. Back then unplugging the projector, waiting for a minute and plugging it in again solved the issue for the last few hours of use but now the problem came up again.
You can watch a video of the problem here: http://youtu.be/aY5IEQQy8-4
This time it happened wathing a movie more than an hour in. My guess that it might be either a thermal problem or that a part is starting to fail.
Any tips on which part I should have a look at first? I have spare power supplies, a mainboard and most probably spares for the boards located between the tubes but would rather like to locate the problem before trying to replace part by part as the error seems only to happen when the unit has been used for a while.
Thanks in advance.
Edit: None of the fault lights on the back turn on when the error is happening.
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Nashou66
Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY
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Nycon
Joined: 10 Apr 2007 Posts: 34 Location: Germany, NRW
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Link Posted: Thu Jan 08, 2015 9:12 pm Post subject: |
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There is no sound or noise when the tubes go black. When they turn on again there is just the usual crackling sound that can alwys be heard when the projector is turned on (same as any CRT tube I suppose, our old TV produced a similar sound).
I had cleaned the HV leads when I checked the power supplies the first time when I had the problem with the image blanking for very short moments. I will take a look at the leads from the splitter to the tubes again and will try a spare HV supply. I just was not sure whether the problem ir originating somewhere in the HV power chain or if another board shuts the HV off temporarily for some reason.
Will try the spare HVPS and report back. If anyone else has an idea please feel free to comment.
Thanks again.
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stridsvognen Guest
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Link Posted: Thu Jan 08, 2015 9:16 pm Post subject: |
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Try vacum clean the connections to the LVPS and HVPS, and then clean the contact points on both supplys with some isopropylalcohol.
They normaly collect a lot of dust in there.
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Curt Palme CRT Tech
Joined: 08 Mar 2006 Posts: 24296 Location: Langley, BC
TV/Projector: All of them!
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Link Posted: Thu Jan 08, 2015 10:36 pm Post subject: |
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Usually it`s the HVPS that`s going bad, but disconnect the CRT socket from the motherboard, one connector at a time, leaving the other two tubes operational. See if the disconnection of one CRT socket brings it back to life.
Also, a bad H deflection board can cause HVPS shutdown.
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Nycon
Joined: 10 Apr 2007 Posts: 34 Location: Germany, NRW
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Link Posted: Thu Jan 08, 2015 10:44 pm Post subject: |
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I have cleaned both power supplies (took them apart and vacuumed) and cleaned the contacts with isopropanol about 2 months ago, which seemd to have solved the problem intermittently.
I just swapped the HVPS and did a little bit more cleaning around the red HV cables and the splitter (disconnected the vables from the sliptter, wiped with isopropanol, wiped again with a dry cloth a minute later). More carbon buildup than I thought, possibly inside the tube casing as well I would think.
Upon start I get a good picture but have not tested it for longer. The reason: Just barely audible arcing with the metal case closed. When turning the projector on small arcs can be seen on the front of the green tube.
Video here: http://youtu.be/KrZ5wQVcuTY
The black isolation tape around the HV lead from the power supply is just there to hold the plastic tubing around the wire together, broke it slightly while mounting as the plastics turned a bit stiff after years of storage.
I can't really tell if the arcing might have also been present before the swap as it is really hard to make out with the case closed when not paying utmost attention. I think a also hear slight arcing inside the tube assembly after the louder arcs that can be seen on video appear. You might be able to hear it in the video.
Further advice? And after cutting off the power, how long do i need to wait to access the HV leads, e.g. for disconneting them from the splitter? I guess testing whether the tubes still start to shut down after some time is not advisable with arcing inside the machine.
Thanks for your help so far.
Edit: Almost midnight here, if it helps I can post a few pictures of the insides of the power supplies (should be really clean) and a better view of the projector tomorrow. Maybe I really have to take the whole thing apart for cleaning... From visual inspection the capacitors in the power supplies looked okay
Last edited by Nycon on Thu Jan 08, 2015 10:47 pm; edited 1 time in total
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Curt Palme CRT Tech
Joined: 08 Mar 2006 Posts: 24296 Location: Langley, BC
TV/Projector: All of them!
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Link Posted: Thu Jan 08, 2015 10:47 pm Post subject: |
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Pull the HV leads out and touch them to the chassis without handling the tip or anywhere close to it. Do that, and you can pull the HV leads out of the splitter 30 seconds after powering down. Worst case you`ll get a small spark.
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Nycon
Joined: 10 Apr 2007 Posts: 34 Location: Germany, NRW
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Link Posted: Thu Jan 08, 2015 10:48 pm Post subject: |
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@curt: Thanks.
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stridsvognen Guest
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Nycon
Joined: 10 Apr 2007 Posts: 34 Location: Germany, NRW
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Link Posted: Thu Jan 08, 2015 11:33 pm Post subject: |
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Okay, will do that. I guess it will have to come down from the ceiling to do the cleaning properly and in a safe manner
Thanks guys. I will report back once the unit is cleaned.
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stridsvognen Guest
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Link Posted: Thu Jan 08, 2015 11:37 pm Post subject: |
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You can just let the chassis hang, its easier to take it down in pieces.
When they are that dirty i normally strip all the coils and magnets off the tubes to, and clean it all up.
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Nycon
Joined: 10 Apr 2007 Posts: 34 Location: Germany, NRW
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Link Posted: Fri Jan 09, 2015 1:51 am Post subject: |
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Okay, not having to take the beast down is somewhat a relief. I am a bit hesitant to take the coils and magnets off the tube as I really do not want to mess something up. I have checked the "advanced procedures" section here which has photos of the inside of a tube assembly, if I understood correctly then some of the magnets are glued on... I gues I will leave them on. What would you advise to use for proper cleaning? Paper towels? sllightly damp paper towels? Display cleaning wipes?
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Nashou66
Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY
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Link Posted: Fri Jan 09, 2015 2:06 am Post subject: |
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Looks like the HV lead that connects right to the tube bell might be where its arcing.
You can remove the top of the plastic cover I think by removing all the screws and it will will come off.
not sure how many but if you investigate then you might be able to see it more clearly.
Check the rubber cup that is glues to the tube bell. It might be the source of the leak. you might need to replace that
lead or add some silicon or HV rubber tape to isolate that arc.
Athanasios
_________________ Don't blame your underwear for your crooked ass~ unknown Greek philosopher
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stridsvognen Guest
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Link Posted: Fri Jan 09, 2015 6:54 am Post subject: |
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I normaly use some glass cleaner on spray, blue stuff, must be alcohol with silicone or something like that for those electrical parts, and wash the plastic parts with hot Water and soap.
Justin will be the Expert here, he have the cleanest Marquee ever seen, its cleaner than any Marquee who left the factory.
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jbmeyer13
Joined: 03 Dec 2010 Posts: 1135
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Link Posted: Fri Jan 09, 2015 3:06 pm Post subject: |
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stridsvognen wrote: | I normaly use some glass cleaner on spray, blue stuff, must be alcohol with silicone or something like that for those electrical parts, and wash the plastic parts with hot Water and soap.
Justin will be the Expert here, he have the cleanest Marquee ever seen, its cleaner than any Marquee who left the factory. |
LOL...I try to keep it looking good
I use denatured alcohol to clean just about everything; PCB, plastic tube assemblies, HV Leads, etc. For bellows I generally clean them first with denatured alcohol and then apply a vinyl dressing (Vinylex) to prevent the rubber from drying out. For the optics I follow this: http://www.curtpalme.com/Lens_Cleaning.shtm
Having decent micro fiber cloths and small soft bristle toothbrushes help greatly when removing all of the black conductive crap that gets all over the cases and boards.
Also, when cleaning boards that are really filthy first use an air compressor to blow off as much of the loose stuff as possible, then use a dry horsehair auto detailing brush to remove the layer that is caked on. As a last step you use the small toothbrush with denatured alcohol. Using this method prevents the alcohol from turning all the dust into wet gunk which is harder to remove from the board.
_________________ Projector: Modded 9501LC ULtra- MP VIM, Vold VNB, ETECH LVPS, Silver VIM Cables, HD10F's & a V1 case!
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draganm
Joined: 08 Mar 2006 Posts: 8990 Location: Colorado
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Link Posted: Mon Jan 12, 2015 9:31 pm Post subject: |
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Nashou66 wrote: | Looks like the HV lead that connects right to the tube bell might be where its arcing.
You can remove the top of the plastic cover I think by removing all the screws and it will will come off.
not sure how many but if you investigate then you might be able to see it more clearly.
Check the rubber cup that is glues to the tube bell. It might be the source of the leak. you might need to replace that
lead or add some silicon or HV rubber tape to isolate that arc.
Athanasios |
Nash is right, on a lot of older Marquee's they used a loose fitting boot where the HV wire comes out of the bell. Over time, that cavity gets filled with black conductive soot, and will start arcing.
Unscrew the HV splitter block, un-clip all the leads, and just let it hang down. Disconnect the Horizontal board leads, then remove the metal covers over the tubes ( the one arcing going to it). Remove the plastic cover right behind it.
Then remove the upper half of the plastic tube enclosure- 2 large flat-head phillips screws in front , 2 Phillips down in the holes on the sides towards the front-middle, and 2 small ones at the back.
the upper half of the tube cover will now comes off completely and can be scrubbed in the sink with dish soap and brush.
You will now see the boot and the HV wire. This needs ot be cleaned with Isopropyl, and use a Q-tip to clean inside the boot cavity thoroughly. You want to be thorough here, until the Q-tip comes out clean.
fill that cavity with Clear 100% pure Silicone RTV . Let it cure for at least 24 hours. If your in a really cold or low humidity location, wait 48 hours.
the re-assemble.
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Nycon
Joined: 10 Apr 2007 Posts: 34 Location: Germany, NRW
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Link Posted: Tue Jan 13, 2015 10:20 am Post subject: |
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Thank you for your input. I had a few thing come up so I did not have the time to work on my Marquee. As soon as I do I will post an update here.
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Nycon
Joined: 10 Apr 2007 Posts: 34 Location: Germany, NRW
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Link Posted: Tue Apr 21, 2015 10:10 am Post subject: |
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Sorry for the late reply. I only got around to woring on my projector last week. I removed the tubes from the chassis whie mounted on the ceiling, pretty easy job when you have someone who supplies an extra set of hands.
I removed the tubes from the plastic casing and completely cleaned them and also applied HV silicone between rubber cut and HV cable.
Everything is now working aithout faults, so thank you very much for your input.
One thing I noticed after putting everything back together: The image is now about 10% lower than before, for all tubes. I am pretty sure that the tube sit flush with the chassis as the pivot pins are all in the appropriate mounting holes and the screws to fix the tubes fit and are tightened pretty firm. I also have a problem with fitting a few screws of the covers, so eomething seems not to be mounted correctly. I curently do not have the time to take everything apart again to see what I might possibly have messed up.
Anyways, thanks again. You guys are awesome!
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