Light/fan dimmer causing ground loop problem...long - sorry

[MCF]

I have been battling a random 'wave/trickle' on my plasma screen for the last six weeks. I tried all the typical solutions - in line filters for cable box, isolating the ground on the plasma (I know, bad idea - didn't help so I removed the 'cheater' plug), checked all connections, etc. etc. I even posted on this forum looking for advice and nothing seemed to help. Then yesterday, I emailed my problem to a high end audio/video store here in Houston and to my shock, they actually called me to discuss even though I had not bought anything from them. After a couple minutes of talking, the store guy asked if I had a light dimmer...I told him I installed one for the recessed lights and a ceiling fan controller a while back - not sure when, but seems to be around when I started seeing the wave. He said take them out and that this happens all the time. Well, I disconnected both of them last night (not just turned off, but took off one lead from the switch after throwing breaker of course) and it solved the problem 95%!! Only one wave in three hours...then I remembered I also installed a dimmer in the dining room...open floorplan with living room and dining room the same. He said today to disconnect it as well and that should do it. Has anyone ever heard of anything like this and have I really solved the problem or maybe last night was just a 'good' night for my system???

[edtyct]

Gee, I remember wondering out loud whether you had installed any new electrical thingy recently. We got fixated on the servo sub, didn't we? I remember you saying something about a garage door opener, or a security system, no? Anyhow, don't look a gift horse in the mouth. If extracting the dimmer did the trick, hooray. Congratulations.

[StanleyMuso]

mix. I had a serious buzzing problem in my equipment for quite a while which I could not track down. I even took my amp back to the store for checking, to no avail. Then one night I noticed that the buzz was a lot worse when the lights were dimmed. I took the dimmer out, and hey presto, no more buzzing.

[MCF]

But it looks like it was the dimmer and fan controller. Question...I disconnected the two in the living room and the one in the dining room (open floor plan with dining room right next to living room). Watched entire movie of Gladiator last night but I still saw the ripple once or twice (I think) - much better than once or twice every 15 minutes. I have a dimmer and a fan controller in my upstairs bedroom directly above the living room where all the audio/video equipment is installed. You think I should get rid of those also!?!? Secondly, any experience with a Panamax 5100? A local place is offering to sell me one with a full cash return guaratee if it does not completely eliminate the ripple...they want $299.

[edtyct]

Try removing the other dimmer and fan controller first, if you're willing to live without them; it could save you $300 on the Panamax, assuming that Panamax would even work. But, if the Panamax is returnable, it's certainly worth a try.

[Glen B]

I have been battling a random 'wave/trickle' on my plasma screen for the last six weeks. I tried all the typical solutions - in line filters for cable box, isolating the ground on the plasma (I know, bad idea - didn't help so I removed the 'cheater' plug), checked all connections, etc. etc. I even posted on this forum looking for advice and nothing seemed to help. Then yesterday, I emailed my problem to a high end audio/video store here in Houston and to my shock, they actually called me to discuss even though I had not bought anything from them. After a couple minutes of talking, the store guy asked if I had a light dimmer...I told him I installed one for the recessed lights and a ceiling fan controller a while back - not sure when, but seems to be around when I started seeing the wave. He said take them out and that this happens all the time. Well, I disconnected both of them last night (not just turned off, but took off one lead from the switch after throwing breaker of course) and it solved the problem 95%!! Only one wave in three hours...then I remembered I also installed a dimmer in the dining room...open floorplan with living room and dining room the same. He said today to disconnect it as well and that should do it. Has anyone ever heard of anything like this and have I really solved the problem or maybe last night was just a 'good' night for my system???

I guess I missed seeing your earlier post asking for help. Yes, dimmers, speed controllers and certain halogen lights are notorious for causing RFI problems as well as humming/buzzing in power transformers. In the latter case (not your present issue but nevertheless related and I think worth mentioning for future reference) this if from DC being injected into the AC power line. Removal of the offending device(s) is the only solution.

[MCF]

one guy asked how close my tv is to my refrigerator!?!? Has anyone had a refrigerator kicking on cause a ground loop? I do not have the problem with the AC kicking on and off...this is a new home with up to standard wiring so I would not think that a new fridge kicking on would cause a ground loop with a plasma tv.....I think people are starting to reach now to solve this problem....

[edtyct]

MCF, I agree that we're all reaching a bit, but the circumstances warrant it. Besides, a ground loop is not the only electrical phenomenon that can affect your system. Appliances, such as a refrigerator, apparently can send shivers through the wiring that audio and video components can pick up. You may not notice it in sound but maybe in sight. The mere fact that you have a new home that conforms to the local electrical code doesn't guarantee that your equipment is protected from anything. I feel for you. I wish that you could get the use of a P.S. Audio conditioner for a week or so.

Ed

[MCF]

Thanks for your help...Panamax recommeded a line conditioner...for $1500...even if I could try, I would not want to because if it solves my problem, I still don't want to spend $1500. Is there less expensive lind conditioners I could try? I believe Circuit City carries PS now....you can take anything back there. Any specific model number??

[edtyct]

Offhand I can't recommend a model. When I have time, I'll be happy to take a look at PS's current crop. But someone mentioned going to the PS Audio site. Ask there for a model, based on as concise a description of your situation, and finances, as possible,

Ed

[MCF]

Still having problem with my horizontal wave moving up the screen. I literally disconnected each component one at a time (signal line and power supply) until I was sending a signal from my dvd player to the tv directly via a component cable. A company suggested that the 'hum bar' I experiencing is a result of a ground loop and is likely due to cable tv. When I was doing my tests, I had the signal line coming out of the wall for the subject tv disconnected and the power to the time warner box unplugged. The cable line was plugged in to three other tv's in the house and the tv's were plugged in but off. Is it possible that the cable signal going to the other tv's even though they were off could result in a ground loop with my main plasma tv?? I simple test is to unplug the main cable feed outside the house and watch a DVD I guess. Any thoughts? Also, a $300 Monster Power Bar with level 2 conditioning did nothing to solve my problem so it got taken back to Circuit City right away for a full refund.

[PAT.P]

Mcf is your 3 way spitter grounded at your cable line .Pat.P

[MCF]

Not sure. Would the splitter be outside the house? Inside the house in the box that houses all my elecronics for my alarm is also where the main cable feed comes into the house. Here, the feed goes into a signal booster and then to a splitter where the cable lines are routed throughout the house. How would I check to see if the splitter is ground?

[PAT.P]

Not sure. Would the splitter be outside the house? Inside the house in the box that houses all my elecronics for my alarm is also where the main cable feed comes into the house. Here, the feed goes into a signal booster and then to a splitter where the cable lines are routed throughout the house. How would I check to see if the splitter is ground?
Mine is where cable comes in house (around fuse box ) from there I have a splitter going to my three tv .It is grounded to my fuse box. The splitter should always be grounded.Pat.P

[hermanv]

If you have a local electronics "surplus" store. They will most likely have 1 to 1 isolation transformers also commonly sold as 110 to 220 converters (may have to move the voltage taps) These will cost a lot less than a commercial power line device and will effectivly remove any DC componnent from the power line. Get one rated at the next size up from your TV's wattage.

I've have also seen couplers to remove ground loops from the "F" connectors if you are using one for your antenna input.

Also note that a defective TV can have this problem.