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Post by barclay66 on Apr 30, 2018 4:14:29 GMT -5
Hi,
Mixing balanced and unbalanced signals often creates problems. I assume that the processor's output is a XLR socket, correct? And the amp only has an RCA (cinch), correct? You culd check the adapter cable that You use for connecting them. It should be built like this:
What is the noise from the center channel like? Is it a humming, hissing or crackling noise?
Kind Regards, barclay66
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Post by barclay66 on Apr 24, 2018 14:20:49 GMT -5
Hi,
Regarding the third question: With a multimeter set to continuity check (or set to ohms measurement if there’s no continuity check option), measure for continuity between the metal outer ring of any cinch connector and the earth contact of the power plug (the longer one in the middle). That should tell You if signal ground is connected to earth potential or not of either device.
That ground screw terminal usually is only used for turntables which have an additional ground wire.
With ground loops there usually are only two options: Either separate the ground potentials using isolation transformers or similar technologies (using optical connections work too) or force both devices onto the same potential by connecting both signal grounds to the same grounding point via thick wires. There should be a lot information on the web. Try searching for ‘eliminate ground loop’ or similar.
Another two questions: Are processor an amp connected to the same wall plug? If not, try it out. Can You try a different amp for the center channel? That would eliminate a possible problem with the center preamp output...
Kind Regards, barclay66
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Post by barclay66 on Apr 24, 2018 6:19:38 GMT -5
Hi,
First question: Did it work without the noise at some point or is it that it has been there always? Second question: If the noise appeared at some moment, did You change anything in Your setup and what? Third question: Is the earth connector of the Magnet amp connected to the outer contact of its chinch plugs? Fourth question: Is the earth connector of the Marantz processor connected to the outer contact of its chinch plugs?
I want to get a clear picture of the problem first...
Regards barclay66
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Post by barclay66 on Apr 9, 2018 3:52:56 GMT -5
Wow! What a butchered mess!
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Post by barclay66 on Feb 19, 2018 4:31:40 GMT -5
Hi,
Finally, I got around replacing the resistor packs at HDMI input #1. Good thing is that I could do that without having to remove the board. I only had to remove an air duct which was covering it:
This shows the defective resistor packs. Please note the four small craters on each of them:
This is the area after removing them and cleaning:
These are the new ones in place:
Now the unit is fully functional again!
Kind Regards, barclay66
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Post by barclay66 on Feb 19, 2018 4:15:36 GMT -5
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Post by barclay66 on Feb 19, 2018 3:57:28 GMT -5
Hi,
More than two years ago, I prepared and refilled the tubes I have been using since on my Marquee. The stuff I used is from a local dealer (sells all sorts of paints and solvents for artistic painters). The tubes now have more than 7000 hours on them and there are no signs of corrosion, fungus or anything...
Kind Regards, barclay66
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Post by barclay66 on Feb 14, 2018 4:10:31 GMT -5
Hi,
Thank You for this opportunity (not that I had been lurking around waiting for it ). I hope that this place continues to be a platform for the exchange of ideas, knowledge and experience and -of course- a resource for those looking for help in repairing their gear.
Kind Regards, barclay66
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Post by barclay66 on Feb 12, 2018 9:49:23 GMT -5
Hi,
BTW2: I never understood why they would use 250V caps on the CVA although the supply voltage is only 24V per rail. Any ideas?
Regards, barclay66
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Post by barclay66 on Feb 12, 2018 9:43:59 GMT -5
Hi,
BTW: The +/-24V rails are being used on the FGM, the +24V go to the HDM and the -24V to the belly fans. Any of these could feed some 'dirt' into the supply. If this 'dirt' had the right frequency, it could create interference with the convergence amplifiers and their pulsating current draw...
Kind Regards, barclay66
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Post by barclay66 on Feb 12, 2018 9:31:23 GMT -5
Hi,
Were You possibly referring to the 'ground strap fix'? I've downloaded the relevant posts from 'somewhere else'...
Kind Regards, barclay66 Attachments:Ground Strap fix_2P.pdf (583.24 KB)
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Post by barclay66 on Feb 5, 2018 7:09:06 GMT -5
Hi,
I went for a rather "brute force" approach as the chip was dead anyway: I took a very fine needle which I could use for going under the pins, applied a solder blob on each side, added some additional flux and went heating each side while lifting the pins with the needle. All pads were left unharmed. After that, I cleaned the area with solder wick, positioned the new chip and soldered the outward pins to their pads. On each side, I then applied flux and fresh solder creating solder blobs again. After removing them using solder wick and after cleaning, the result is like in the pictures. Before doing all this, I practiced on an obsolete hard disk controller board.
The marquee is still being used on a daily basis. Before working on mods and testing, I still have some other projects ahead:
- Arduino-based RS232 control for selectively controlling all of the AV gear. I want to be able to selectively switching on/off all devices in the correct order for a signal chain ending up either at the Marquee or at the Sony. So, each of them will require adequate output settings on the Lumagen (e.g. 1080p24 for the Sony or 1080p72 for the Marquee when watching Blu Ray) and an individual power up and power down sequence (e.g. leaving enough cooling time for the Sony). I will control the Marquee, the Sony, the Denon amplifier and the Lumagen via RS232 and will apply power to them via relays. The only unit being constantly powered will be the remote box itself.
- Modifying my son's active speakers (the ones I built last year) for balanced inputs and digital crossovers (Yamaha D1030/DDL3)
- Building my own active speakers (Toslink inputs, DSP-based active crossovers, ICEpower digital amplifiers, remote control)
- One or two smaller repairs on audio gear
Kind Regards, barclay66
P.S.: You're a moderator now? When did this happen?
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Post by barclay66 on Feb 5, 2018 4:28:06 GMT -5
Hi,
It works! Well, at least HDMI Port #2 (which is sufficient to me). HDMI Port #1 will now return EDID data to the source but there's no picture. Later I found out why: I didn't check the resistor packs at the switcher's inputs! Those are clearly dead too and I overlooked that. I might finish the repair some time in the future and only if I have to open up the unit anyway: The QA board is buried under the optical block and disassembly takes some time. In the pictures You can see the switcher chip after replacement, the PCB area with defective parts removed and the same area after replacement. I had to add one wire jumper due to the disintegrated trace and for one transistor and the double diode I didn't get the original parts but replacements with a different case...
Kind Regards, barclay66
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Post by barclay66 on Jan 30, 2018 9:21:36 GMT -5
Hi, I would check all of the diodes involved (maybe there's some leakage current) and would check all of the connections and cables for continuity. What happens if You switch on the unit and after that remove the 40 pin flat cable? Another check could be around the MCU for good soldering and/or any contaminants between the legs. Also check for glue blobs. Check this out: alpengeist-tvrepair.blogspot.ch/2017/03/onkyo-a8470-speaker-relais-not-clicking.htmlRegards, barclay66
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Post by barclay66 on Jan 29, 2018 7:39:43 GMT -5
What you're not getting is that with non-Thomson yokes the centering is already good to begin with! No adjustment is necessary! What little adjustment may be needed can be achieved WITHOUT using raster centering via convergence, other than perhaps a small adjustment for vertical offset. The only reason Thomson yokes have the centering feature is to compensate for their OWN bad design! Hi, Raster centering controls have to be available always IMHO. E.g. when adjusting the flare magnets, You always will have some amount of raster movement and this should be correctable... Regards, barclay66 P.S.: Please don't draw this discussion into some fruitless contest (e.g. "My knowledge/vodoo/balls/whatever is bigger than Yours, so shut up and worship me!). I always believed that we could do without at least on this forum. And I don't complain about the valuable information part of Your posts, it's just how their tone is set. P.P.S.: And yes, this partially applies to Kurt too.
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