CurtPalme.com Home Theater Forum

rs454 · Posted: Sun Apr 08, 2012 3:52 am Post subject: Marquee high voltage pop

While watching a movie the other night the Marquee (8500) let out a loud pop and the pic went off then it came back for a few seconds then popped again. It did this 3 times before I could get it turned off. The arc seems to be coming from the hv cables near the hv splitter. I pulled and cleaned each cable from the splitter and replaced them then powered on the projector.It was on for about 20 minutes and it happened again. I was thinking about covering the cables with clear tubing like the lead from the power supply. Is this a common issue and is there a better solution? Thanks Rich

CasetheCorvetteman · Joined: 09 Nov 2008 Posts: 6326 Location: Australia

Put abit of neutral cure silicone on there where its arcing, and allow it a couple days to cure. Or replace the lead.

draganm · Joined: 08 Mar 2006 Posts: 8990 Location: Colorado

**Curt Palme** · Posted: Sun Apr 08, 2012 6:05 pm Post subject:

What Dragan said. You're lucky you didn't fry the H board, as each arc can nuke it. I'd change all three HV leads and the splitter to be safe, and to be good for the next 10 years. I've got stock of everything if you need it,

dturco · Posted: Sun Apr 08, 2012 6:53 pm Post subject:

rs454 · Posted: Sun Apr 08, 2012 7:44 pm Post subject:

Happy Easter and Thanks Everyone It seems to coming from a cable near the splitter bu I am afraid to leave it on long enough to see exactly which cable for fear of damaging something. I do have a parts projector. Could it hurt to put some dialectric grease or silicone on the plastic sleeve above the connector ? Thanks Rich

draganm · Joined: 08 Mar 2006 Posts: 8990 Location: Colorado

it always "seems ot be coming from the splitter" because that black sooty grime on the HV wires is conductive. The leak will start at the bell of the tube, then travel up the wire and arc to the card cages or lens mounting plates. you can certainly put as much RTV silicone around the splitter as you want.
When your done with that take the plastic covers off the tubes and see if any of your boots look like this.

Tim in Phoenix · Joined: 21 Oct 2006 Posts: 4409 Location: Phoenix

Hello

The clear tubing is more to prevent cuts of the leads on sharp edges than anything else; PVC has little insulating value at 35000 volts. Look for a dark pin-hole spot on the pink wire. If the leak is on the HV supply lead then you may be able to shorten it a few inches and reattach the Hobson connector.

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CasetheCorvetteman · Joined: 09 Nov 2008 Posts: 6326 Location: Australia

And careful using black RTV, some of that is conductive too.

draganm · Joined: 08 Mar 2006 Posts: 8990 Location: Colorado

DB Cooper · Posted: Mon Apr 09, 2012 2:27 am Post subject:

look at the front of your splitter where the glass resin is. Look for any pin holes. I had one do the exact same thing, and it was arcing through a small pin hole in the resin. Don't know what caused it to burn through there, but it did. Replaced the splitter and all was good.

rs454 · Posted: Mon Apr 09, 2012 11:05 am Post subject:

I have checked the cables and do not see any burned spots or smudges anywhere. I did not see where the spark originated from but it did jump to the hdm card cage. The closest cable to the cage is the one going to the hvps. I close tonight so I will have some time to work on it later this morning. Thanks Rich

Tim in Phoenix · Joined: 21 Oct 2006 Posts: 4409 Location: Phoenix

Hello

Do you see a burn on the HDM cage? If it is next to where a scan yoke plugs in, then the arc is from the anode rubber cup on that tube and the arc has jumped to the yoke wiring. Take the tube top metal covers off of all three tubes and run the projector in the dark; you should be able to see a strong spark where the high voltage is leaking.

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rs454 · Posted: Mon Apr 09, 2012 6:44 pm Post subject:

I cleaned all the connections to the splitter and resealed them using dialectric grease (on the plastic sleeves). I turned it on and right away I got another pop . This time I got a much better look at it. It seemd to be coming from one of the lower cables. I replaced the splitter and I noticed a small black line just above the lower cable.I think that got it . Its been going for 2hours and no arcs. Thanks Rich

draganm · Joined: 08 Mar 2006 Posts: 8990 Location: Colorado

rs454 · Posted: Wed Apr 11, 2012 10:44 am Post subject:

Thanks for the tip I did not know it would work if the splitter was not wired correctly. I double checked and it was correct. Is there anything that can be done to the one that was arcing or for that matter to the working one to prevent this from happening again? Thanks Rich

DB Cooper · Posted: Wed Apr 11, 2012 12:30 pm Post subject:

Yep, throw that one away! Not much you can do for it other than hope it doesn't happen again.

draganm · Joined: 08 Mar 2006 Posts: 8990 Location: Colorado

these things are readily available so no need to attempt repair . I bet Curt has at least 50 in a box somewhere.

rs454 · Posted: Thu Apr 12, 2012 2:41 am Post subject:

Ok I will just get another one to replace it.I watched another movie last night and it had no issues. I want to reset it and redo the complete setup. Thanks Rich