When you disconnect all external speakers and/or stereo or mixer, etc and just play through the internal speakers do you still get the noise? If not then you have the Dell ground loop.

Symptoms would include a scratchy staticy noise when moving the cursor, and the noises occurring only when attached to another device while plugged into the power adapter. Here are my thoughts on dealing with the ground loop, if that is the problem:

1. Eliminate the ground either on the computer or on the other device it is connected to, by using a 3 prong to 2 prong adapter. This fix should only be used for diagnosing the problem ... if this eliminates the noise use one of the other solutions for long term.

2. Or isolate the grounds from each other by using a ground isolator or a direct box with ground lifter. Some members have given us positive reports on Radio Shack's $16 Ground Loop Isolator (270-054). There are more expensive isolators which might give better audio results.

3. Or use non-conducting material to connect the 2 devices; specifically by using optical spdif to transfer the audio signal rather than copper cables.

Jim