There is a loud buzz/hum throughout my home audio system.

mcmuffin72, pretty broad question you are asking. It will depend on how you have it connected, what you connected to it and what you have checked so far. Most common hum would be a ground loop hum. PITA to determine which component causes it. Typically you will have a ground loop when the buzz/hum comes out of your loudspeakers.

To determine where the ground loop originates from you will have to first determine if it is an audio issue or a video issue. If it’s a video problem, the try to use a known good source like a DVD player, game console etc. and see if it changes. Always use good shielded video cables. If the hum comes from the audio, then the first suspect is always the power amp that is driving the loudspeaker. To see if it is the amp, disconnect its inputs and turn it back on again. Go back to the speaker and place your ear in close proximity to see if the hum is still there. If it is, then you have a problem with your power amp. now you will have to let us know what audio system you have so we can may be help you out a bit more. If it is not, reconnect one input at a time to see which component causes the hum.