H/K AVR7300 "Hum"

[WndrBr3d]

Recently I've noticed that when I turn my H/K AVR7300 on, the speakers will *pop* then you can hear an audible 'hum' (probably ~60hz) coming from every speaker on the system.

anyone have any immediate ideas what might be causing this?

i've double checked the wiring to my speakers and it's fine. i've checked the power source by plugging it into multiple outlets, power strips and power filters with the same result.

any help is greatly appreciated!

 

[Buckeyefan 1]

It could be a ground loop issue. Try unplugging your cable box. If it still does it, unplug your sub. (just trying to localize the problem) A 60Hz hum usually comes out of the sub, but I haven't heard this one yet. Next advice would be to call HK and ask them.

 

[WndrBr3d]

the sound isnt coming from the sub because the tone isnt being generated in the preamp. i think it's something with the acutal built in amp.

 

[WndrBr3d]

i think i may have "fixed" the issue.

i was also getting cross talk to the rear speakers while in stereo mode. i figured something in the unit was touching where it shouldn't (whire touching a heatsink or something along those lines).

i took the unit and sorta "jiggled" it to try and get whatever was touching, away. turned on the unit, no pop, no hum and no cross talk.

caveman logic still works sometimes. if it doesnt work, just bash it until it does

 

[WndrBr3d]

Just an update on this issue!

Took my receiver into an authorized Harman/Kardon repair center, where they said that there was a screw loose in the amp which was grounding out the transformer.

Anyways, got it back now and everything is great!