[mythtv-users] [OT] - irritating buzzing noise

[Brad Benson]

On Thu, 4 Nov 2004 22:36:50 +1100, Phill Edwards
<phill_edwards at hotmail.com> wrote:
>  
> Thsi is a bit off-topic so apologies in advance. I have just built an FC2
> box to run mythtv and have everything pretty much up and running (so a
> tenuous link there) but in the last couple of days a really irritating
> buzzing has started. The machine boots up into run level 3 fine but as soon
> as it reaches the point where it puts up a login prompt at the end of the
> boot the PC speaker starts emitting this horrible buzzing sound. (I'm not
> booting into X windows yet until I get absolutely everything sorted). The
> only way I can stop it is to disconnect the speaker wire. Does anyone have
> any idea what this might be? I'm a bit nervous in case it's some sort of
> hardware problem alert or something. 
>   
> Regards, 
> Phill 
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> 
> 
> 

I had a similar issue several months ago.  It turned out that I had a
ground loop between the PC itself and the cable tv connection.  To see
if that's your problem you can get one of those 3-prong->2-prong
outlet adaptors like this:
http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=61-2720
and use that to connect your PC's power cable to the outlet.  

THIS IS NOT A PERMANENT SOLUTION.  Leaving that power adapter in place
will cause your PC to be ungrounded and this can cause serious harm,
including electrical shock to anyone that touches that PC.

If using that power adapter removes the buzzing noise then you have a
ground loop.  I can't recall right now the link to the adapter you
need to remove that noise, but if you google on '"ground loop" "cable
tv" buzz hum' you should be able to easily turn up several pages with
more info.  I fixed my problem by connecting together two of those old
adapters to convert VHF/UHF antenna signals to a coax cable.  You just
attach the terminals on the two adapters together and attach one coax
adapter to your wall jack and the other to the cable coming from the
wall jack.