# Could a bad hdmi cable be the cause of 60hz speaker hum?

I was at a friend's house trying to help him get his computer/tv/stereo connected in his new apartment. We had some difficulty getting the tv to acknowledge the video signal. The hdmi source option was intermittantly available depending on the position of the cable. So it's a bad cable and needs to be replaced.

But we wanted to do as much diagnosis as possible in case anything else had been damaged or lost during the move. So we carefully placed the cable and backed away slowly and selected the source.... (Wait, wouldn't that be a great opening for a spooky story? Sorry, back to reality.)... Then testing the computer audio through the receiver, there is a very bad 60-cycle hum coming through the speakers. It's still there if we switch to the internal tv speakers and disconnect the receiver.

If the audio is running from the mini-headphone-out (I kept wanting to switch it to line-out, but it didn't ever help) to RCA-ins on the tv, could the bad hdmi cable be introducing this hum even though no audio (in use) is going through that cable? Or does this implicate the stereo-mini-to-rca cable as well? Or is it likely to be something else entirely?

Now, don't let me forget to mention that there's hum in the air already. The apartment is on the side of the building with the A/C pen for 2 apartment buildings (about 20 of them). When we turned everything off, we could distinctly hear the same buzz (maybe a little more pink) from outside. And I could also hear a little bit from the refrigerator in the galley kitchen about 10 feet away from the living room.

So, any ideas, etheric masters?

• @luserdroog "check the headphone jack with headphones. And I think we can bypass the tv and run the audio straight to the receiver" - please do that. no real point in advising anything now until we know more. – Jon L Jun 5 '12 at 4:58