I have a friend who has a low-frequency hum on his receiver. I've done some troubleshooting over the phone, but have reached the end of my experience. The hum is still there with all of the sources and the display disconnected from the receiver, it is even present when the receiver is powered down. The hum is coming from both speakers. Is the receiver bad or could it be a grounding issue? Any next steps in troubleshooting?

Thanks in advance,
CJ

What is the make and model, how old is it, has it been serviced before, has it ever experienced a lightning strike event....?

It hums when it's turned off? Does it have a rotary speaker selector? If so, turn it to Speakers B, if is only has one pair connected. If it stops the hum, it has problems.

Where are you located? Do you have electronics shops that do service work? If not, look for a regional place to do the work.

As I understand it.
All Sources disconnected; Hum
Receiver Powered down (but not unplugged); Hum

Sounds like radiated noise from another source.

Is the AVR a Grounded power plug?
If so, float the ground with a cheater plug.
If hum persists run an extension cord (three prong) to another outlet that is on a different circuit breaker and then text me.

Another question- what is this receiver sitting on? Need more info.

Is it connected to TV cable on fm antenna input on receiver.
We once in a blue moon. get hum bar or audio hum through amp until we remove from cable company or have cable company feed grounded to house groung

Scooper, that won't happen with the amp's power off.

cj, have him unplug the receiver from the power. The list of things you've tried doesn't include that yet.

A client once had hum from a subwoofer. After all sorts of stupid tests including unplugging everything, I told him he was hearing the refrigerator that was on the far side of the wall from his system. That fridge had been there for years, but when the client got a sub, he focused on bass and finally heard the hum he'd ignored for years.

Maybe that sound has been there all along. I couldn't tell over the phone what my client's problem was, and you'll have to visit your friend.

Came across the same problem, a water pump was continously humming away in the roof space due to a small overflow problem.
You would have sworn it was coming from the speakers!

Damn. I figured Ernie would be asking those questions :) I'll find this out.


It hums when it's turned off. I'll find out if it has A/B speaker selector and try it out.


I'm in the Charlotte area. We used to have one, but it closed. I'll look around if it ends up being the receiver.


Correct.


When he disconnects the speakers, the sound goes away, so it's coming from the speakers.


It is.


I was planning on doing this but I didn't realize that you could get a ground hum with the receiver off. Apparently you can, so I'll have him try this next.


No idea, but I'll find out.


No, it is through HDMI. Hum was still there when I had him disconnect it.


Thanks. It goes away when the speakers are unplugged, so it's not from another source. I should have mentioned that in the original post.

I appreciate all the help!
CJ

Bad receiver.

was it plugged into an old NEC monitor?

he may have to buy a new house due to incompatibility issues..

I ask those questions with every post. You ignore my signature, which is just like ignoring the question to begin with, since brand and model numbers are the starting place for any thread! It's like this:
Q. My car smells like a diesel! What can I do?
A. First -- is it a diesel?


If the problem were described correctly, we'd be ahead here. Either the receiver hums when it's turned off, which you determine by putting your ear down TO THE RECEIVER, not the speaker, that's totally different from "I hear a hum from the speakers when the receiver is off.  Or on.  Either way."  Or whatever the exact details are.


Which is to say the accurate description is that the sound is coming from the speakers.  This makes it sound less like the fridge in the adjacent room, but try this: put it back together so that it hums and disconnect the speaker wires at the receiver end.  That way you won't be moving the speakers around and perhaps upsetting some mechanical thing that's letting hum go through the speakers.  That sounds crazy, but the whole thread does, so what the heck.


I don't think you can.  However, if a speaker wire is shorted to the power ground somewhere, I suppose that's possible.  Nobody, myself included, mentioned to check for shorts between the speaker wires, when disconnected, and power ground.


That eliminates whatever is connected to the other end of those HDMI cables unless there's also an analog audio cable to one or more of those components.


WAIT.  Speakers unplugged?  Is this a sloppy choice of words or is there something about the speakers that makes them plug into the wall power?

See the second half of my signature.  Be sure you're using the right term. When someone speaks of "a technicality," realize that the path to the solution here is the exactly correct technicality, that is, using the technically correct word and description of everything... such as the receiver humming or the speakers humming... by the way, do both of the speakers hum?


You're welcome.  I hope it does at some point actually become help.


WTF does that mean? Let's say it's a misspelling: was the post too long for you to proofread it? Or were you too busy looking for an off-topic to post about?


Love it. Reality collides with hilarity.
 

I've had a couple recently,

- Samsung 8000series LEDTV that hums at about 10khz caused by rear panel vibrating

- A Cambridge CD player with a bad internal ground solder from the main board to the analog audio outputs (60hz) feed through all AVR sources

- A Fireplace Fan that hums at about 60hz

as well as the usual suspect Fridge, Subwoofer (with RG6 being used as the input connection), and HVAC systems.

There's nothing in particular about RG6 that should cause hum, though if the sub is not on the same phase as the rest of the system, things might be improved with a cable having a lower resistance shield. DC (well, 60Hz is almost DC) resistance that you can measure with a regular old DC Ohmmeter.

10KHz is NOT a hum, that's called 'buzz'. 'Hum' is a lower frequency sound.

To : FunHouse Texsas


Nice one Centurion!