My 5 year old BV 3 has started to make an intermittent deep buzzing sound. It seems to come at random and irregular intervals and seems to come from behind the brush aluminium plate. It's not coming from the speakers.

Any ideas what might be wrong?

 

Is the Beovision 3 working correctly other than the deep buzzing sound, in particular is the picture perfectly correct ?

Keith

Yes everything else seems to be OK

Phil

Phil,

Good, well the following additional questions come to mind on this one:-

1. You say it is intermittent, but does it happen a lot after you have just switched the set on, or is there a period of time before it starts?
2. You say its seems to be coming from behind the brushed aluminium plate, can you please clarify exactly where you think the buzzing is coming from.

Keith

Thanks for the quick response.

I'll check out the answers to your questions tonight.

Regards

Phil

If it's only when powering op it's the degauss. But don't think it's that you mean. If I'm right it comes randomly when there is white on the screen! it happens because the tube use more power then normal, and there comes a 50 Hz buzzing sound from a trafo in the power supply, that also gets the plastic cover to vibrate, very bad... there are 3 things to do... change the tube [:'(] or spay paint the power supply with lacquer... or ignore it... sorry

(seen 3 that has done this, change tube in 2 of them and spay painted the last... this is not a problem in avant because it made of wood)

Keith

Buzz is not when you first switch on.

Sound comes from the base of the set, not the screen or the speakers.

Bang 1

I'll check to see if it's linked to white on the screen, but it does sound like what your describing.

Can you explain why/how sprying the transformer helps please?

 

Thanks to both of you

Regards

Phil

blackbird160:

 

Can you explain why/how sprying the transformer helps please?

 

Spraying the transformer basically replaces any laquer which was originally applied to the copper wire windings as an insulator and to also to stop the transformer vibrating. Obviously you won't get them same degree of penetration as was originally applied but I've heard of this being done before with good results.

 

Chris.

You can try to disconnect the RF antenna. I have the same problem with my BV3-32 (5 years old).

I think the problem is in this way. 

see  Medogsfat's post,

Thanks to you all for the advise.

I have tried the Ariel; no change.

So the next step is to spray the transformer: where about is it? Do I need to remove it or can I spray it in situ? And is there any particular lacquer that I need to use?

Phil

Phil,

My last post in response to your comments got lost in the forum running out of capacity, so I will re-state my answer.

The area you say is buzzing is also the area of the power supply and EHT transformer (Extra High Tension) and the buzzing is normally caused by what is known as Eddy currents which are around all magnetic devices such as transformers. The buzzing you are hearing is caused by something loose and so the eddy currents vibrates whatever is loose. In older transformers there was a lot of thin steel plates bolted together to make the laminations and these would come loose and buzz.

When others suggest spraying a transformer, I would suggest this is not a good idea particularly the ETH transformer which generates upwards of 25,000 Volts for the tube anode and arcing can easierly occur.

Also, if there is nothing apparently loose then this may be the first signs of a potential failure if more current than normal is being drawn via a transformer and taking it outside its normal working spec which would also cause a buzzing.

Are you a technical person with some knowledge of TV's like the BeoVision 3, who with direction could make some checks to define the root cause of your problem ?

Hi it's the power supply thats the issue, it's placed on the left, inside the chassis. there is brown trafo about 6 cm high.