Plasma Buzzing Sound

[Frank3y3]

Not so sure if it's the right place to post this question, but here it is:

Is the buzzing sound on any plasma because of high power driving the panel ?

It doesn't really bother me that much, I should say it doesn't bother me at all. But I do know it buzz louder when the screen is fill with white content. If I'm right, there's a board in charge of turning on pixels, which in this case, white color, do buzz louder, and there's another board which turn off the pixels, am I right ? If yes, what's actualy causing the buzz, screws, coils, transistors, panel frame.....

Frank
And I'm french, i guess you notice !

[tom66]

Re: Plasma Buzzing Sound

It's caused by two elements

- constant buzzing, non-altitude dependent is caused by coils and capacitors on the SC, SS and P boards.
- buzzing dependent on altitude or outside pressure is caused by the panel glass itself

A plasma display is sustained about 200,000 times per second with varying modulation, typically around 600 partial frames per second for 60 frames per second. More for newer panels like VT20/25. This causes the panel, coils, capacitors, etc to vibrate slightly in time with this, creating audible sound.

As for why altitude alters buzzing, the panel gas is under quite low pressure, around 5 to 10 torr (~650 to 1300 pascals) compared to atmospheric pressure around 100kpa. This means as pressure drops with altitude, the panel is more able to vibrate due to lower overall pressure.

Power? What power? Oh, the ±200A pulses going into the panel 200,000 times a second. That ought to make it buzz a little! Frankly, I'd be worried if it didn't buzz!

[Frank3y3]

Re: Plasma Buzzing Sound

Well, now I know why, informations : Plasma 101 by Tom66.

Thanks for the info.

[tw2005]

Re: Plasma Buzzing Sound

generally you should not notice it too much. If any of the sustain boards mounts are loose that can amplify the noise. Also i did read somewhere there was a quality issue with the PSU on the V20/ VT20?, maybe only the 50 " but can't remember now but apparently there was a large transformer which would crack in the core. May have been just our version . I only hear a faint buzz with my V20 if I'm right at the set and the volume is down, which is normal.

My SC would be very loud when i was rebuilding them and got slack not putting all the screws in or not tight. Otherwise I have no complaints really.

http://www.avsforum.com/t/1327177/fo...ic-plasma-2010

[Frank3y3]

Re: Plasma Buzzing Sound

Interesting, i've check the link you provide, great great post. I'll try the Ty-rap thing and check for coils, transformer and tight screws. I think it also reverberate a bit much because of proximity walls, near 1 feet behind the TV, 25 feets/foot ceiling resonate, also near a window. Like you said, i'm hearing it with the volume turn down and facing the TV at the same height mostly. Always interesting reading these posts.

[tw2005]

Re: Plasma Buzzing Sound

The zip tie really from what i saw was for an obviously cracked transformer.

[Frank3y3]

Re: Plasma Buzzing Sound

Yes it was, haven't had the time to take off the back and take a look at my 2 TVs. Still waiting for some parts, actualy i bought a TC-P50VT20 for 100$ ( 60 euro ) for parts, the screen is broken. And though i could use the D Board for my TC-P54VT25 ( Board only was 135 $ shipped ) so i bought the the broken TC-P50VT20 instead. Can't wait to put my hands in it again. Yep....

[tw2005]

Re: Plasma Buzzing Sound

Yes it was, haven't had the time to take off the back and take a look at my 2 TVs. Still waiting for some parts, actualy i bought a TC-P50VT20 for 100$ ( 60 euro ) for parts, the screen is broken. And though i could use the D Board for my TC-P54VT25 ( Board only was 135 $ shipped ) so i bought the the broken TC-P50VT20 instead. Can't wait to put my hands in it again. Yep....

Glad you clarified that, I was wondering whether you were at 2 or 3 TVs or had a mishap with the 50. With respect to the broken screen, if you are hanging onto the parts it's a good idea to do some routine checks of the Buffer boards and the SC.

I say this because if the TV was powered when the screen was hit then the panel can short and damage those.

I'm talking from experience on this one because I too purchased a complete board set from a 50VT20 cracked screen and after checking ,the lower buffer was shot (shorted)but the SC seems ok and powers up in my V20 without a blink however i do not have a 3D to hook up and confirm it produces a normal image but chances are it should be fine since it's not shorted.

The Sc alone would be worth more than what you paid let alone adding other valuable bits like the A board and I guess now too that the one blink was on the D board then I expect people would be looking for those boards as well.

I have read and seen digital noise or image problems in the VT20. I know on my V20 the processor under the heatsink runs bloody hot and often wonder about the lifespan of it.

[Frank3y3]

Re: Plasma Buzzing Sound

Again and again, usefull informations here. I should receive the broken TC-P50VT20 sometimes next week. And yes, after reading your post, i'll check every boards and......

Maybe you could help me at that time to troubleshoot and confirm if the boards or ok ? I do have a better understanding of these TV's since I took a look at them with y'all last time. And i would be all excited again to get my hands in it for another third VT20/25 serie's TV.

When you say : I have read and seen digital noise or image problems in the VT20 ?
Can you explain a little ?

Grainyness, color bending, partial color hint....( don't know if i say this correctly, those are technical words )

[tw2005]

Re: Plasma Buzzing Sound

http://www.youtube.com/watch?v=cfObEv-MwGg

All you need to do resistance check the buffer boards the same as the non 3d model and check SC2 is not shorted.

if it's not you could swap it into your other one for final confirmation, likewise for any other board too except i would not do this for the buffer boards.

A shorted buffer can blow the SC which is the main reason i was mentioning this, don't assume they are ok. imagine if they were bad and installed them into a Tv with a good Sc only to blow it up.

I've done this and a very expensive mistake especially now as they are hard to get and expensive.

Up to you how far you want to go, there's always a risk when pulling things in and out of making a mistake or damaging ribbons etc.

[Frank3y3]

Re: Plasma Buzzing Sound

Well, hope my 2 VT20/25 won't end up like the one in the youtube video !

Thanks for the Troubleshooting Handbook. Thanks for the Info like always.

Here's mine :

[Frank3y3]

Re: Plasma Buzzing Sound

Sorry, a little late, had some problems to take care of :

Here it is:

[Frank3y3]

Re: Plasma Buzzing Sound

Here's the second Part :

Pages 91 to 143

If anybody needs it for the VT20/25, 50 and 54 inches.

[Trelkovsky]

Re: Plasma Buzzing Sound

Hello , I bought a new samsung plasma tv and is making an annoying buzz like in this video:

https://www.youtube.com/watch?v=FvkJmcyynB4

Note:This video is not mine, but my tv makes the same noise.

Is this normal? The loudness of the buzz can vary depending of the model?

In other forums, people with the same tv model as mine, says that his tv is silent even with the volume down.

Sorry for my bad English.

[tom66]

Re: Plasma Buzzing Sound

It's normal for some newer plasmas. It seems to be "luck of the draw" if you get it on the newer models. All plasmas buzz, but the level should not be audible beyond about 1 foot. If it is, there is a problem and I would have the TV exchanged.

[michael4wave]

Re: Plasma Buzzing Sound

- constant buzzing, non-altitude dependent is caused by coils and capacitors on the SC, SS and P boards.

as soon as I plug in a sound cable I start hearing unpleasant buzzing.
Its soo annoying I cant really watch my tv. have to watch it on mute.
or output sound.

question, is there a quick way to test a what cause it ?
or should I replace power board straight away.

[tom66]

Re: Plasma Buzzing Sound

as soon as I plug in a sound cable I start hearing unpleasant buzzing.
Its soo annoying I cant really watch my tv. have to watch it on mute.
or output sound.

question, is there a quick way to test a what cause it ?
or should I replace power board straight away.

It would be a good idea to include your TV's details such as make, model in a separate thread.
Your issue sounds like a ground loop have you tried another cable because a bad ground connection can cause the same symptoms.
Is the fault also present on HDMI or digital TV audio. If the TV has an internal sound generator (for example Samsung TV that makes a chime) is that also affected?

[hispeck]

Re: Plasma Buzzing Sound

Hello, talking about vibration and buzzing sound on plasma, I have samsung 43h4100, once powered on , no picture no sound, It's only vibrate