Originally Posted by paris_tn
adamwc, i just found this and it is nothing really new. Put some pillows behind it and see if this absorbs some of the buzz and let us know. I read this, the increase refresh from 75 to 100 worked best by lowering the tone of the buzz. They say it still buzzes but at a differ tone and is some better.
Plasma panel buzz is a normal phenomenon. Plasmas work on a totally different principle to colour televisions and have different operating characteristics. The level at which the operating buzz becomes noticeable is always subjective; one person may hear it whilst another does not. The following points help to understand the factors surrounding the buzzing:
The picture scanning drive circuits operate at high frequencies and powers. It is these circuits that cause the buzzing sound. The circuits are used to create both the picture and reuse energy to keep the unit efficiency high and panel heat emission low. This over-heating control is very important on the panels that do not use fans i.e. 37” and 42”. The resulting loss of fans makes for a quieter panel operation.
Due to the very high amount of power processing required, the 50” panels have cooling fans (up to 4), which will also contribute to the overall noise these plasma panels will produce. The buzz will appear more concentrated at the sides of the unit where the power circuit boards are situated.
Where cooling fans are not employed, the buzz may be heard in very quiet surroundings. Plasma buzzing is normal and will always occur, but the level of buzz is what matters.
Generally speaking the buzz will only be heard in quiet surroundings (with low levels of audio from whatever sound system used) and with the userseated too close to the panel - less than 12’ for 42” and 10’ for 37” panels.
A typical scenario is using the panel in the middle of the night when listening to news broadcasts at low volume. In this situation buzz might be heard during the silent breaks in the audio, but not so much during speech. This is not abnormal nor does it indicate a faulty panel.
If the buzz is heard above normal ambient daytime noise and audio levels at more that 12’ a problem might be present.
The method of panel installation will also affect the amount of noise heard. Wall mounting the panel will cause buzz emitted from the back of the panel to be reflected off the wall and into the room more than if the unit is located on the pedestal which is seated 2 to 4 feet away.
Plasma panels do not run in total silence. They do buzz as a normal part of their operation, but this level of buzz is quite low and may beintermittently noticed in quiet surroundings, many factors can influence this.
Changing the picture mode in the picture settings menu between dynamic/normal/cinema will also reduce the level of perceived noise since this affects how much power the panel is processing and this the level of power produced.
Having too much brightness and contrast with the dynamic mode setting on,can overdrive the panel and cause louder buzz levels with strong picture signals i.e. DVD or Sky digital signals. Changing these settings can lower the level of buzz produced. Use ‘normal’ picture mode and lower brightness/contrast settings to reduce this effect.
It is normal for the buzz tone and level to change the picture content because the panel drive circuits are processing different amounts of power and adapting their drive cycles.
Hard wall surface i.e. painted/wooden panels will be more effective reflectors than say walls that are covered in softer finishes, wall papered or curtained.
Please ensure these facts are understood and check your panel against a dealers display unit before requesting service, since abnormal levels of buzz are not always ‘abnormal’ but just the normal operating buzz of plasma technology.