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Discussion Starter #1
My week old Panasonic 42PC77U had a buzzing problem from day one. It was not very loud but was noticeable 5+ feet away when the room was quiet. I've hunted various buzzing/humming problems in my 2 channel music rig and previous HT setups. With the plasma, it buzzed as soon as it was plugged in without any other cables connected so that eliminated a ground loop however the buzzing was not always present. At times, it was completely gone.


I then tried my balanced power isolator which may have done a little but didn't significantly reduce the buzzing. Today, I considered the halogen lights in the basement. They are on a completely different circuit, a floor apart and the other side of the house. As I suspected, when my wife hit the switch for the basement halogen lights, the buzzing went away. I am pretty certain that the problem comes from EMI caused by the lights or other sources in my house. This set being a budget one may not have a well schielded power supply while other sets have better parts. Also, this does explain the intermittent problem I experience and the fact that a few others reported 2 or more sets buzzing. Hopefully this observation will help others find a solution to their buzzing problems.
 

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My Pio 5010 buzzed from even 10' away....and this was when all the lights in my house were turned off. Had it also plugged into a Monster HTS1600 .


Maybe my fridge was the cause for the buzzing - it was an old fridge, probably 20years and it ran really loudly. Ah well, I don't have the Pio anymore, and neither the fridge but wish I had thought of this before and tried unplugging the fridge or other appliances in the kitchen.
 

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Quote:
Originally Posted by Chris_B /forum/post/12900840


My week old Panasonic 42PC77U had a buzzing problem from day one. It was not very loud but was noticeable 5+ feet away when the room was quiet. I've hunted various buzzing/humming problems in my 2 channel music rig and previous HT setups. With the plasma, it buzzed as soon as it was plugged in without any other cables connected so that eliminated a ground loop however the buzzing was not always present. At times, it was completely gone.


I then tried my balanced power isolator which may have done a little but didn't significantly reduce the buzzing. Today, I considered the halogen lights in the basement. They are on a completely different circuit, a floor apart and the other side of the house. As I suspected, when my wife hit the switch for the basement halogen lights, the buzzing went away. I am pretty certain that the problem comes from EMI caused by the lights or other sources in my house. This set being a budget one may not have a well schielded power supply while other sets have better parts. Also, this does explain the intermittent problem I experience and the fact that a few others reported 2 or more sets buzzing. Hopefully this observation will help others find a solution to their buzzing problems.

Good job. Tell me, are the halogen lights controlled by a dimmer? Sometimes a dimmer can introduce RF and cause electronic items to buzz. Also, it's not likely that the halogen lamps themselves are causing the buzzing so it must be something else related to that circuit. Is it possible that you have too many halogen lamps on that circuit? Add up the number of lamps and mulitiply that by the number of watts each lamp puts out. If they're on a dimmer, too many lamps will overload the dimmer (typically rated at only 600 watts) and that can cause the dimmer to introduce a buzz into the circuits.
 

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Discussion Starter #6
Yes, they are on a dimmer. I'm using ten of the little MR16 50 watt bulbs so it is close but not over the rating of the dimmer. The dimmer does buzz (even when I only have a couple fixtures on the bar. The buzzing does come from the dimmer itself. Now I just keep it off and I have the peace of mind knowing that it is not a faulty power supply in the plasma.


Now I do think that the Panasonic PX77/75 (and PC Costco version) do have an inherent propensity for buzzing due to EMI. Other sets such as sma's above seem to have a different buzzing problem.
 

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Quote:
Originally Posted by Chris_B /forum/post/12911337


Yes, they are on a dimmer. I'm using ten of the little MR16 50 watt bulbs so it is close but not over the rating of the dimmer. The dimmer does buzz (even when I only have a couple fixtures on the bar. The buzzing does come from the dimmer itself. Now I just keep it off and I have the peace of mind knowing that it is not a faulty power supply in the plasma.


Now I do think that the Panasonic PX77/75 (and PC Costco version) do have an inherent propensity for buzzing due to EMI. Other sets such as sma's above seem to have a different buzzing problem.

That dimmer should not be buzzing so there is something wrong with that lighting circuit. I sell dimmers and low-voltage recessed lighting to electrical contractors and usually a buzzing dimmer is some sort of mis-match of incompatible components or an overloaded dimmer. Some possibilities are:


1. The dimmer is a line voltage model (120v rated) not a "Low Voltage" model.


2. The dimmer is indeed a low-voltage model, but it's designed for low-voltage fixtures with a magnetic transformer but your fixtures have a cheap potted electronic transformer. Or it's an low-voltage electronic dimmer and your fixtures have magnetic transformers.


3. The dimmer is overloaded, or is max'd out wattage wise (i believe the total wattage of the bulbs should not exceed 75% of the rating of the dimmer). A magnetic Lo-Vo dimmer (Lutron SLV-600P for example) is typically rated at 600 watts so with 500 watts in your ceiling you may be a bit over the derated limit depending on what all you have there. And the Electronic Lo-Vo dimmer (SELV-300P) for the cheap lights is only rated at 300 watts, but i don't know if it has to be de-rated 75% like the regular one. I mostly sell only commercial stuff nowadays so i'm a little hazy on the fine details of the residential side of my industry



If you can, pull the dimmer out and give me the brand name and model number off the sticker (like Lutron SLV-600P etc). Give me all the info on the sticker.


Also, find out if your recessed fixtures have magnetic transformers (the big heavy black kind like used on your doorbell) or if it's a solid-state electronic transformer (like the chinese-made fixtures come with). And if you could tell me the brand and model number of your recessed can lights that would help me as well. There is usually a big sticker where the bulb goes with this information.


Lemmy know the details of your dimmers and fixtures . . . .
 

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Quote:
Originally Posted by RandyWalters /forum/post/12904913


Good job. Tell me, are the halogen lights controlled by a dimmer? Sometimes a dimmer can introduce RF and cause electronic items to buzz. Also, it's not likely that the halogen lamps themselves are causing the buzzing so it must be something else related to that circuit. Is it possible that you have too many halogen lamps on that circuit? Add up the number of lamps and mulitiply that by the number of watts each lamp puts out. If they're on a dimmer, too many lamps will overload the dimmer (typically rated at only 600 watts) and that can cause the dimmer to introduce a buzz into the circuits.


Man, I wish I had read this a few days ago. I just filled out all the paper work for a home I'm having built. My wife really wanted recessed lighting hooked to a dimmer in the family room. We went with 6 recessed lights in the family room and 4 more in the master bedroom both on a dimmer switch. Those are the two places we plan on putting plasmas too. To change it now would cost $200 per room and mean a conflict with my wife. Is it worth it? Can I just put in bulbs under 100 watts and be ok? I really don't want loud buzzing tvs. We also have an open floor plan with the fridge maybe 20 feet from where the plasma will be. I beginning to think that we have create a less than ideal environment for hdtv viewing.


edit: would buzzing be eliminated if the dimmer is set to off or if the lights are really dim? That is how we would watch tv anyway, so maybe it won't be a big deal (I hope)?
 

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Quote:
Originally Posted by enkidu77 /forum/post/12911900


Man, I wish I had read this a few days ago. I just filled out all the paper work for a home I'm having built. My wife really wanted recessed lighting hooked to a dimmer in the family room. We went with 6 recessed lights in the family room and 4 more in the master bedroom both on a dimmer switch. Those are the two places we plan on putting plasmas too. To change it now would cost $200 per room and mean a conflict with my wife. Is it worth it? Can I just put in bulbs under 100 watts and be ok? I really don't want loud buzzing tvs. We also have an open floor plan with the fridge maybe 20 feet from where the plasma will be. I beginning to think that we have create a less than ideal environment for hdtv viewing.

There should not be any problems as long as the builder uses quality dimmers and recessed lighting and uses compatible quality dimmers. For many many years i sold all the electrical material to a Malibu-based electrical contractor that did pretty much all the homes of the rich and famous in the area and he never had any real problems with dimmers and recessed lighting. I remember full well (many years ago) when some of my other customers started complaining about dimmers buzzing and causing RF that affected the homeowners' electronic equipment where they had never had this problem before. They bought the good Lutron Lo-Vo dimmers from me, but had sourced the recessed lighting from other suppliers (cheap crap) and i figured out that the cheap chinese fixtures were being made with cheap chinese electronic potted transformers, but the Lutron Lo-Vo dimmers were designed for traditional magnetic transformers. I contacted Lutron's tech staff with my concerns and they were aware of the problem with the influx of new cheap overseas lighting and were about to release a line of special Lo-Vo dimmers (SELV-300P) for use with electronic fixtures. This almost completely solved the problem, but some of the cheap fixtures were so crappy that they also introduced RF into the circuit. Changing the fixtures out to a quality brand with magnetic transformers and changing the dimmers from electronic to magnetic models solved the problem.


But i also sold to the big movie studios and they sometimes had major problems with the various 120-volt electronic dimmers causing a hum in their audio recording and interference in their video monitoring equipment so they would often use the older-style rheostat type dimmers to prevent this.

Quote:
would buzzing be eliminated if the dimmer is set to off or if the lights are really dim? That is how we would watch tv anyway, so maybe it won't be a big deal (I hope)?

If the dimmer buzzes, you would probably just have to turn it completely off, or maybe turn it all the way up. I think if the dimmer is actually dimming the fixtures then that's where the buzzing is being introduced so maybe setting it all the way up enables the fixtures to run at full voltage.


But as long as your builder uses good compatible components, and is a capable wireman, you should be fine. You might want to find out the brand and model numbers of the dimmers and recessed housings and make sure they're a good brand, and properly matched.
 

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Discussion Starter #10
Randy,


Here is what I know. The halogen lights are on a Hampton Bay track that says 19EF / HB555-258 / HB5013. The fixtures are Hampton Bay 19EF HB555-184 BHT 0001. The dimmer is a cheap Lutron that I think I need to replace. There wasn't a label on it so I don't know else to describe it other than a rotary dimmer.


My fixtures look like this:



Also, as you noted, the buzzing increases in volume when the dimmer is between off and all the way up.
 

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Quote:
Originally Posted by Chris_B /forum/post/12912529


Randy,


Here is what I know. The halogen lights are on a Hampton Bay track that says 19EF / HB555-258 / HB5013. The fixtures are Hampton Bay 19EF HB555-184 BHT 0001. The dimmer is a cheap Lutron that I think I need to replace. There wasn't a label on it so I don't know else to describe it other than a rotary dimmer.


Also, as you noted, the buzzing increases in volume when the dimmer is between off and all the way up.

There's your problem right there. Those track heads have an electronic transformer in the rectangular base, and your old rotary style Lutron dimmer is absolutely not for use with any sort of Lo-Vo lighting (be it magnetic or electronic, recessed or as in your case, track lighting) so there's your problem. Get that dimmer out of there for now because it's a possible fire hazard - put a regular wall switch in there for now if you want to continue to use those track lights until you correct everything. I bet this is the one you have:

http://lutron.com/rotary/?s=17000&t=17200




Also, even if you were to install an electronic Lo-Vo dimmer (like the SELV-300P), you still have way too much total wattage so you'd have to remove some of those track heads to bring the overall wattage load down to the correct level for the dimmer.

http://lutron.com/skylark/?s=17000&t=17200


Another choice would be to find some line-voltage track heads that take regular halogen screw-in bulbs (the 50PAR20 size is popular) and ditch those Lo-Vo heads and keep your old rotary dimmer.
 

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Discussion Starter #12
Thanks for the great advice Randy. At this point, I'm just going to go with a regular wall switch. Are there any concerns there or are they all created just about equal for this application?
 

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Quote:
Originally Posted by Chris_B /forum/post/12912818


Thanks for the great advice Randy. At this point, I'm just going to go with a regular wall switch. Are there any concerns there or are they all created just about equal for this application?

So is that the rotary dimmer you have? (push-on/off, knob splined like how a steering wheel slips onto the steering shaft)?


It's a very old model and was popular well before the MR16 type fixtures came on the scene, and before Lutron started putting stickers on all their dimmers with the catalog number and wattage rating information.


Any cheap regular wall switch will be fine, like a toggle-style Leviton 1451 series or their rocker-style 5601 series. But leave that dimmer turned off for now and change it out ASAP. Don't use it unless you're in the room. I know you've probably been using it for a long time like this with no other problems, but it is a hazard. I bet it gets pretty warm to the touch when you've had the lights on at like 80% for a few hours . . . . .
 

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Discussion Starter #14

Quote:
Originally Posted by RandyWalters /forum/post/12912933


So is that the rotary dimmer you have? (push-on/off, knob splined like how a steering wheel slips onto the steering shaft)?

I think that is the dimmer and it does get warm. I don't really even use it for dimming anymore so a regular toggle wall switch will be fine.


Thanks again for the great advice.
 

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Just discovered this thread, and I'm very hopeful that the dimming can lights in my theater room are what is causing my new 58B560. I'll report back, but thought this deserved a bump in case it solves anyone else's problems as well...
 
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