speaker hum, not headphones?

[stan505]

where should I start looking for a problem with my receiver, I have a very noticable hum in the speakers. even with all components disconnected it still hums, any help?

 

[Resident Loser]

Are there any...

...AC cords running parallel to signal leads?

...Components disconnected...at which end? The reciever or at the component?

...Is the unit grounded?

...Is the AC outlet grounded?

...Is the hum actually only audible with the speakers and not with 'phones?

...How high is your volume setting? AND is the hum apparent in actual use?

The last may seem a stupid question, but...if you have the volume high enough with no signal, you may just be hearing the 50 or 60 Hz AC line frequency that is present to some degree in most electronic gear.

jimHJJ(...specificity is required...)

 

[stan505]

...AC cords running parallel to signal leads?

no

...Components disconnected...at which end? The reciever or at the component?

nothing is connected to the receiver

...Is the unit grounded?
yes

...Is the AC outlet grounded?
yes
...Is the hum actually only audible with the speakers and not with 'phones?
yes
...How high is your volume setting? AND is the hum apparent in actual use?

with vol. completely low, it is very apparent, it did not do this until about 1 month ago, no warranty.
any suggestions?

 

[Resident Loser]

Well...

...if you have a separate ground wire, you might try disconnecting it to see(or rather hear) what happens...

A month or so ago? Any thunder storms or power surges you can recall? Changes in house wiring? Any utility work at all...cable, phone? Is it sitting on or near a new TV or other component?

I mean you could try a different AC outlet, but that is really being optimistic about the whole thing...a probably a complete waste of time and only postponing the inevitable.

Suggestions? I think we know where this is probably going...it's been my experience that 'phones ususally are driven by the power amp through a voltage divider, so any trouble would be apparent on both them and the speakers. This unit may use a different scheme, so it's probably a problem in the power amp section or in the segment of the power supply that feeds that section.

jimHJJ(...sorry...it may be time to consider other options...)