Loud humming noise coming from connected devices on Onkyo reciever

[hsbdobergirl]

I have an Onkyo TX-SR674 receiver. Now, when my connected devices are turned on (Satellite receiver, Blu-Ray player) I get this loud humming sound coming from the speakers it happens on both HDMI inputs. If these connected devices are not turned on, there is no humming. I can't figure out the problem. Any guidance appreciated! Thanks, Dallas

 

[americanaudiophile]

You seem to have a ground loop problem.
If the units are plugged into different AC outlets or power strips change that.
Sometimes you can use a 3 to 2 ac adapter on the receiver to break the loop.
http://www.cablewholesale.com/products/power-products/power-cords/product-30w1-32200.php?utm_source=GoogleShopping&utm_medium=cpc&utm_term=30W1-32200&utm_campaign=3%20Prong%20to%202%20Prong%20Grounding%20Converter%20for%20AC%20Outlet&gclid=COmHv9Kd-84CFUxahgodlSIFjw
You may already have one in a drawer somewhere.
Alternatively you could try adding a ground connection from both sources to the receiver. Won't be that easy as many components don't have a chassis ground available. Any screw that contacts metal would be OK.

 

[jsmithepa]

The most common problem is GROUND LOOP. That's a fancy term for bad/old electrical wiring in your house.

1. Make sure all components are plugged into the same outlet, use a power strip if you have to.
2. One component at a time, see if you can reverse the electrical plug (it may not let you). Unplug from wall, turn the plug 180 degree, so left prong is now on the right and viceversa.

If none of these help, you need an electrician.

 

[hsbdobergirl]

You seem to have a ground loop problem.
If the units are plugged into different AC outlets or power strips change that.
Sometimes you can use a 3 to 2 ac adapter on the receiver to break the loop.
http://www.cablewholesale.com/products/power-products/power-cords/product-30w1-32200.php?utm_source=GoogleShopping&utm_medium=cpc&utm_term=30W1-32200&utm_campaign=3%20Prong%20to%202%20Prong%20Grounding%20Converter%20for%20AC%20Outlet&gclid=COmHv9Kd-84CFUxahgodlSIFjw
You may already have one in a drawer somewhere.
Alternatively you could try adding a ground connection from both sources to the receiver. Won't be that easy as many components don't have a chassis ground available. Any screw that contacts metal would be OK.

 

[hsbdobergirl]

The most common problem is GROUND LOOP. That's a fancy term for bad/old electrical wiring in your house.

1. Make sure all components are plugged into the same outlet, use a power strip if you have to.
2. One component at a time, see if you can reverse the electrical plug (it may not let you). Unplug from wall, turn the plug 180 degree, so left prong is now on the right and viceversa.

If none of these help, you need an electrician.

 

[hsbdobergirl]

americanaudiophile and jsmithepa. Thanks for posting. All the devices were already on the same circuit via power strips. I could not reverse the plugs. I tried plugging the receiver in a completely different circuit. Tried putting one of the offending devices on a different circuit. I unplugged everything and started down the line. I tried everything I could except "Alternatively you could try adding a ground connection from both sources to the receiver. Won't be that easy as many components don't have a chassis ground available. Any screw that contacts metal would be OK." I didn't know how to do that. I just know enough to be dangerous...

So I thought let me check the non USB connected devices. Interesting, if I put the receiver on the tape slot, and the VHS is unplugged, I get that humming noise and the VHS is not USB. When I play the VHS, the sound comes thru just fine, there is just that annoying humming going on. Same for the radio and old multi-CD player. If I put the receiver on the DVD or Blu-Ray slot which is USB and they are powered off no humming. When I turn one or the other on the humming starts. The humming happens whether the TV is connected or not. This problem hasn't always happened at least not on the USB. I haven't used the other devices in a very long time (VHS/Radio/CD). I can't remember when it started but it's been a while and I just haven't had time to mess with it and I just dealt with the annoying hum. I question if it's old/bad wiring - the house is less than 10 years old but then again anything is possible. The only good thing to come out of this I finally labeled all the cables. If I have to get an electrician what do I tell him? Ground loop problem? Any other thoughts? Maybe the receiver has gone bad...