Background hum from stereo

benevolus2 wrote:

2oldman wrote:
I'm assuming this is on shore power?

It occurs on shore and battery

It runs directly from battery?

2oldman wrote:
I'm assuming this is on shore power?

It occurs on shore and battery

I'm assuming this is on shore power?

Thank you all for your time and great information.
Just to answer a few questions:I don't have original unit to swap and check, but I didn't have hum with old one. Battery and convertor good.
I will recheck my wiring when I get up to camper next month. I am leaning towards a bad ground or antenna connection.
Again, thanks to all of you.
Steve

I too suspect the bad ground.

On the RCA cables (the coxial cables that connect the A/V out to the A/V in assuming it has them (make sure the "Leaves" of the connector have not spread or..very.,very.very slightly Pinch them

Also you could have a bad cable

if the power plus is a 2 wire type. and NOT polorized (either one of them) turn it over and see if that makes a difference.

I've seen most of the sources I've listed

Sometimes just moving cables around can fix it.

tdst51 wrote:
It is a bad ground somewhere.

X2 Hook a wire to the metal case and touch it to the various items in the system.

Does the unit have an external antenna? I've seen cases where a unit needed an antenna and didn't have one attached and for some reason that allowed it to pick up more background interference from other sources such as lights and electrical appliances. It had similar symptoms as yours with noise while playing the radio but no noise playing a CD. Also, if it has an antenna, check all the connections. A loose or bad connection could have the same effect.

It is a bad ground somewhere.

Maybe it hums because it doesn't know the words?

Baddium bump, I am here all night folks.

But in all seriousness another thing you can check is to make sure no wires are touching any other wires. Like wiring a car stereo speaker set up cheap wiring touching other wires causes feedback such as you describe.

Some LED bulbs will cause hum.