CurtPalme.com Home Theater Forum

[dturco]

I wanted to tie this into one of the previous threads but they were just to mucked up. For clarity I chose a new thread topic.


I was talking to Curt this morning about a H/V lead as the culprit for this Crackle issue. The wise Curt said I don't think it's that, try removing the cover and look for sparks in a darkened room. Well I already tried that several times I said. Curt then says, I have had some people have problems with the H/V splitter arcing. Nope changed that too, I say. Hmm Maybe the H/V splitter is just causing these tiny crackle against the cover? run it with the cover off and see if that helps.

I do, And the crackles stop.

So Now I start to investigate further, Move 1 wire start the machine back up, no difference. OK re-route some wires. No change. Then I thought to myself what about the H/V wires from the HDM Could they be causing this?

Yes They can.

I had the HDM H/V wires bundled together for a neat appearance, the white connectors were on top of each other and discharging to one another, and maybe to the cover and H/V splitter

I separated them and made sure they weren't touching each other, the splitter or cover, I just used wire ties.

No more tiny arcing sounds.

Again I never saw any sparks but could hear the snapping sound of voltage jumping around.

It of course threw the convergence out when reassembled, but that made sense. I re-converged it and the picture is now sharper and cleaner too.

And the test grids also are now more stable, they don't shake around anymore also.


So, Just re-routing wires can cause interesting issues inside a Marquee.

It was so simple

Oh well, fixed for now

Thought I'd share a good one instead of just, I've got issues.

[ecrabb]

I TOLD you it was an HV leak way back in the beginning when you first started asking about the cell phone problem!!! Silly rabbit... I can't believe we even told you it was an HV leak causing the RF, and you didn't think about the fact that you'd tied the HV leads together!

Well, all's well that ends well... You still have issues, though.

Congrats.

SC

[draganm]

how you dress the wires in an electronic device is important. It's why there's a TCB form VDC about re-routing them around the HV splitter. Not to mention all the trouble Athan went through wih his Longbow from the rear heat-sink wires leads being braided together( from the factory).
It seems bundling leads from the same circuit is especially bad because for cross-over noise.

[dturco]

Yep. But the H/V leads weren't tied together, just stacked by each other, like stair steps and pushed together, but same effect my fault

It was the lack of seeing the arcing that screwed me up, well diagnosis wise that is

[Nashou66]

Dave the HDM cables are not really HV, the red ones to the tubes are 30KV the HDM are closer to 1000V. But They do give of a Flyback Pulse that you can see by just getting a scope probe about 4 inches from them. You can see the wave easily on the scope and the closer you get the higher the amplitude.

here is the wave form of the airborne flyback pulse courtesy of Scott(TSE) its the red wave form.















Bundling them together is not a good idea as there is interference between them. HK-Steve tried to even insulate each cable individually with foil wire wrap and more dielectrics but it created even more noise. the noise or EMI from the HDM coil wires needs to be emitted freely or it will cause problems. The only way to shield those wires is to shield every thing else and leave those alone.



Athanasios

[dturco]

Well How I found this little charm was by using an insulated rod { a Screwdriver } that had a magnetic tip. When I got near those wires with it, the convergence on screen went off. So I thought if they are susceptible to the tip of a screw driver, what about each other? Then I separated them, like Dragan mentioned earlier, away from each other and the H/V splitter, and now no noises.

[zaphod]

how's your cell phone?

[Nashou66]

His cell was cleared up way before this.

Athanasios

[dturco]

[menec]

Wow so this thread is really interesting since I suffer from all the issues described by dturco
I'm also having an infrequent crackle of which I can't get rid of and I have the shaky testpatterns as well (most notably on horizontal lines).
I tried to fix the crackle by cleaning all the wires and the boards, by swapping the HV splitter and by re-arranging it according to this TB.

Since the correct routing of all the wires seems pretty important, can anyone point me to some site or TB where the "correct" layout of all the wiring is described or tell me how to do it correctly? Maybe someone could post pics of the inside of a correctly setup marquee

This would probably be useful information for the Marquee "Layout and Setup Tips" section on curt's page as well.

[Nashou66]

Try to keep the HDM wires separated from each other first off, if any wires have to gross each other try to put then at 90 degrees to each other. I tuck the HDM wires down between the tubes away from all other wires if possible, so the connectors are tucked there as well. There really is no way to figure it out 100%, as each set can react differently. Most is trial and error, move the cables button up the machine and turn it on and look if any improvements happen.

Also make sure all grounding cables are secured well, on the VNB cages they can get loose from the metal weakening around where the screws go into it, getting the next size screw will tighten those up.

Athanasios

[AnalogRocks]

[AnalogRocks]

[Nashou66]

[Curt Palme]

[Curt Palme]

[ecrabb]

Nice, Curt. Do they behave when you dress them like that?

[Nashou66]

Ok, All better now. No more messing with your PJ Dave!!!



Athanasios

[dturco]

But I need Thomas Tubes Too.

[cmjohnson]

I could try this or I could just ask: What about the advisability (and effectiveness) of adding snap-on ferrite suppressors to the HDM and other cables in the projector? (But not on the HV leads, as they carry only DC in any event.)

I'm asking because I have access to bags full of snap-on ferrite suppressors in a variety of sizes and specifications. Plenty of ferrite toroids, too.

I believe that a few of these, strategically placed, can do some good in a projector. But I'm not yet sure where they'll do the most
good, or the most harm.


CJ

[Nashou66]

Chris, didn't you se my video on YouTube of exactly what your talking about? I linked you to it in a PM.

http://www.youtube.com/watch?v=P7Eu4RHnle8

Athanasios

[cmjohnson]

Yeah, I saw that, but I'm thinking about the ENTIRE projector, not just the stig board and cables.

CJ