Several of you have commented that you need more information. By 'power 
supply'
I mean that it has the typical 'brick' power supply. It has a 3-foot cord
(3-wire) than plugs into the wall and then a 2.5-foot cord that plugs into 
the
laptop. The 'noise' is not a clear hum but a little more toward a 'frying'
sound or 'static'. It is loud enough when we copy a record (record using the
Mic in jack) to almost totally cover up the music we are recording and it is
loud enough on playback to be annoying. I have an older HP laptop that has a
similar power supply and is the same except that it has a ferrite bead on 
the
cord near the laptop. It has no noise problems. I know of several other 
callers
who have HP, Dell and Sony laptops and have no noise problems. However, I 
have
heard from others that do have such a 'noise' problem. When we unplug the 
power
supply from the computer and let it run on batteries there is no noise. This 
is
not an option because the battery will not last the 2-3 hours that we play
music. I have a clip-on ferrite bead that I plan to try when I see him on
Saturday. It has also been suggested that we try a 3-wire to 2-wire adapter
plug at the wall, but I'm not sure it's a good idea to break the ground 
there.
The 'brick' is plastic and there are only 2 wires running from it to the
laptop, so it probably would be safe. I think I will at least try it to see 
how
it goes.

>A friend of mine just purchased a new HP laptop for the express purpose of 
>playing music at square dances. We discovered that the power supply is 
>generating noise when he tries to play the music and also when he tries to 
>copy music from his record collection (old 45's). What can be done other 
>than running the laptop from its batteries (which won't last long enough 
>for and evening's music)? There is no ferrite bead on the power supply 
>lead. Would that help? Any other ideas? 

                         PCBUILD's List Owners:
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                        Mark Rode<[log in to unmask]>