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RobbieS
06-11-2005, 03:58 PM
Here's the skinny.

Denon AVR-2805, DVD-1910, DCM-380
Hughes HD DirecTivo Box
JVC HR-5902U VCR
Optoma 50" Plasma

Existing House.
Electrician ran a new dedicated circuit to equipment rack. Furman AC-215 plugs into the circuit. All equipment plugs into it via Furman Rack mount surge (don't remember model). Electrician also ran from equipment rack to plasma location a new electrical outlet. In the rack side he just put a male 110 AC plug so we could plug it into the AC-215 which it is.

Now whenever a fan is turned on, Any lights on dimmers are adjusted, and a miriad of other things the Plasma seems to lose sync with the video and the screen goes blank He even has a pinball machine that everytime the ball hits anything that would create a score it loses sync. Picture will re-sync when you finish turning fan on, adjusting dimmers whatever.
Happens regardless of source being watched.

Any ideas?????

Thanks

jritch
06-11-2005, 04:39 PM
Larry should probably wiegh in on this, but it sounds like it could possibly be a problem in the AC circuit. Maybe a loose common or something?

What kind of fans/light dimmers? Are they the Casablanca (or similar) stuff that sends signals over the AC line?

Sounds like one of the messes that I could get myself into.

John

OEX
06-11-2005, 07:39 PM
My first inclination would be a loose ground and/or neutral. Did you check for proper polarity at both the plasma and the equipment? As I read your post it seems the equipment rack and plasma are on a single dedicated ciruit. How about the sub?

What kind of dimmers? I had Leviton microdim dimmers inject tons of noise. I ended up putting noise blocks at each dimmer. The strange thing is the pinball machine effects it too which makes me think its a problem with the AC. How far are your RGB cables feeding the plasma from the AC? Long parallel runs? Can you easily connect different cables across the floor for a test? I would check that if the AC prooves to be ok.

Does it do it with the DVD and cable? Try it with DVD with the cable feed disconnectted from the convertor. This should open the ground loop at that point. Keep us posted.

djnorm
06-11-2005, 11:32 PM
All good questions and suggestions... I would add: try plugging the projector into the wall, and not in the Furman, just to check that they are not somehow unhappy with one another...

RobbieS
06-12-2005, 12:37 AM
Maybe a loose common or something?

What kind of fans/light dimmers? Are they the Casablanca (or similar) stuff that sends signals over the AC line?

Sounds like one of the messes that I could get myself into.

John

According to Mr. Electrician there are no loose grounds or commons.

Standard Hampton Bay & Hunter Fans. No Remote controls or anything like that. Just the wall switch controls.
I think the dimmers/fan speed controls are lutrons.
There are even some standard light switches that cause the problem when you flip the lights off and on.

RobbieS
06-12-2005, 12:44 AM
OEX,

Checked Polarity. All equipment is on a single dedicated circuit. Including the sub.

Lutron dimmers based on the few I checked.
The pinball machine just makes the plasma go nuts.
RGB cable is 20 feet from rack to plasma.
AC lines seperation is good from RGB cable
Will test new RGB cable this week
All sources exibit the same problem. Cable, Sat, VCR, DVD.....
I'll also disconnect cable next time out.

Djnorm,

Tried the plasma without going into the furman, then tried everything without going into furman. I will say there is a LOT of video noise in the picture when I don't use the furman but still have the same problem.

sirroundsound
06-12-2005, 07:48 AM
Have you got anything to test the outlets at the plasma and also the av equipment. See what, if anything, is happening to voltage and current when fans are turned on, or pinball machine is being played. Usually dimmers or other can cause noise in a picture, thats why it's important to make sure equipment and video are on the same phase. Your comment about alot of video noise when not connected to Furman may lead to the above issue. With the plasma, and equipment not connected through Furman, lots of noise, how much noise with pinball off, all fans off and any dimmed lights off? Are there other TV's in house, how do they look? Does the pinball machine interfere with their picture?

RobbieS
06-12-2005, 08:13 AM
Sirroundsound,

Don't have anything to test the AC. I can check to see if both are in phase. I guess sparky could have wired an outlet up wrong.

Even if we go through the house and turn all the fan's & lights off we still have the video noise without the furman.

Pinball doesn't affect any other TV's in the house and they look clear.

the "noise" consists of 2 patterns.

The first is a scrolling bar that scrolls up the screen. It looks like a 60hz hum bar. The odd part is that the scrolling bar is colored. Sometimes pinkish/red sometimes green sometimes blue, sometimes green.

The second are thin lines about 1/4 to 3/8 apart. These lines also look like they may be scrolling up as well. The run at about a 45 degree angle from bottom left to top right. Like this

////////////////////////////////////
////////////////////////////////////
////////////////////////////////////
////////////////////////////////////
////////////////////////////////////
////////////////////////////////////

vwpower44
06-12-2005, 01:42 PM
Definetly check for a neutral and hot reversed. You can pick up at tecter that plugs into the outlet for like 4 bucks at Home Depot or Lowes. I always keep one in the van. Also, you might try putting some ferite beads on the RGB cable, speaker cables going to the TV, power cable, etc. Sounds like EMI to me. If the neutral and hot are reversed somewhere it can seend all kinds of interefenece through the neutral (now hot) .

You could try troubleshooting the electrical side of it, but I am not sure you would want to do thet (Maybe get sparky to do it).

Measure the voltage between Ground and Neutral. There should be little or no voltage. You could also have some sort of inductive or capactive pickup from other wires using transformer (such as halogen lights, dimmers, etc).

Mike

tomciara
06-13-2005, 11:58 PM
The pinball has leaf switches that arc every time you bang a bumper or target. Depending on the age of the pinball they could be switching low voltage or higher voltage AC. This could put out a wealth of radiation. I don't know if a doughnut on the AC cord would help a bit, but...maybe try? What if the pinball were plugged into a fancy power cleaner upper?

sirroundsound
06-14-2005, 07:53 AM
Take something like the DVD player, over to plasma, plug in direct, no receiver or other gear. If you still get alot of noise, then you have a couple of things to concider. Power issues (which it certainly seems like it would be) or you have a plasma that has faults. From your equipment list you have RGB, component and s-video plugged into the plasma? Is there a small TV somewhere you could plug in where plasma is, feed s-video to it and see if same issues come up? (you say it happens on any source) If it happens on a regular TV too, you at least can rule out the plasma as being the issue. Another easy test, get 2 long extension cords, plug equipment into one, run it to somewhere else in house (another room) do the same for plasma (same room). Same issue?

AudibleSolutions
06-14-2005, 07:14 PM
It would seem to me to be the problem is the result of harmonic hash from the motor ( fan ) or dimmers. Why the Furman is not filtering this out is a good question but this may not be RFI/EMI as much as a dirty ( full of harmonics ) neutral. The last time I ran into this sort of problem I used a Triplitte Line conditioner although today I would suggest a sine wave regnerating UPS. Lord, I love this business.

Alan

Kelly
06-14-2005, 07:33 PM
My suggestion?

Since you're in the "I'll try disconnecting this" mode, why not try disconnecting the DTV receiver COMPLETELY from the system.

Quite possibly the ground connection on the line from the LNB is causing the problem. I've had that one before.... 8O

Last time I had an issue like this, I just disconnected EVERYTHING from the PDP, and added one device at a time until the problem reared it's ugly head again.

Time consuming, but it will get the job done.

sirroundsound
06-26-2005, 10:01 AM
Sooooo.... what was the final result?
Did you solve the problem yet?

clinthicum
07-16-2008, 11:36 PM
Anyone here had success with using the following to help correct, diminish, or eliminate EMI issues?

- ferrite choke collars on power cords
- richard gray power company emi "Eliminators"
- argh !


Installed a 50" plasma for a long time customer and he loves to watch B&W movies. Little did I know, before I convinced him to get a plasma, that his old home has EMI or ground loop (or maybe both) issues that would be real prominent, especially while watching crappy 'ole B&W movies.

I've done all the usual stuff to try and show him that I'm doing my best to troubleshoot, but still haven't found the culprit yet.

Also - Anyone had luck with EMI fabric such as that sold by stillpoints . us ?

http://www.tweekgeek.com/_e/Stillpoints_ERS_and_More/product/images/ERSLight.jpg

Theaterworks
07-17-2008, 08:09 AM
First you have to A) describe the problem for us, and B) isolate if it is an EMI problem or a ground loop. What problem are you seeing? B&W images seem to show fainter ground hum bars than a color image.

What happens if you (temporarily, for testing purposes only) install a cheater plug on the end of the plasma's power cord? Does the problem go away? If so, you have a ground loop problem, and there are devices that will fix this safely, or you can mess around with wiring (or have the electrician do it) to correct the problem by changing the circuit the plasma is powered from.

clinthicum
07-17-2008, 02:06 PM
Forgive my ignorance, but what is a cheater plug?
Is it the adapter that lets you plug a typically grounded (3 prong) device into a non-grounded (2 prong socket)?

I haven't tried that yet, but will.

I think I just answered my own question (above)

http://www.enjoythemusic.com/SuperiorAudio/equipment/0107/plug.jpg

My symptoms are slowing rolling (consistent) horizontal lines across the screen. On a B&W movie thru Comcast DVR it looks like a green or pale grey band that starts off with a distinct line about 1/4" thick and running across the entire width of the screen.....

When watching color TV shows, you really have to hunt to find any problem with them image.

Theaterworks
07-17-2008, 02:16 PM
Yes, one of those gray plugs, 3 prong to two prong. From your description it sounds like you have little bit of ground hum. Take a look at Jensen isolation transformers once you've confirmed that's the problem.

clinthicum
08-04-2008, 10:04 AM
Tried the cheater plug, but symptoms persisted.
Installed the RGPC (Richard Grays Power Company) Ground Loop Eliminator device just behind the cable box between the wall jack and the Motorola Comcast Cable DVR input and the symptoms have gone away completely.

The results are outstanding. Fortunately I bought two (2) of the Eliminator products, cause I also installed one for another customer who had some lines rolling thru their TV for a while. And same success there !

I'm going to start carrying these things in with me to all projects; they're worth their weight in gold in my opinon. They retail for $99 but can be had thru distributors for substantially less.
http://store.acousticsounds.com/images/asthumb/S-RG-ELIM.jpg
It only took about 5 min to install the product...much faster than trying to go thru the client's home and find the source of the problem.