40. Why do I hear a buzz or hum when my computer is connected to an external speaker system?

This could be caused by a "ground loop". This happens when the ground on your computer and the ground on your external amplifier have a difference in potential. If you are using a laptop with a 3 prong plug and are connected to AC power, try unplugging the power cord (use battery power) and see if you still hear the buzz. If not, chances are you have a ground loop. You may be able to use an isolation transformer or even just a 3 prong to 2 prong adaptor to resolve the problem. There may be safety issues to consider, so you should consult a technician or the computer manufacturer for more specific advice.

Alyssa - PG Music