Fisher Stereo Receiver Humming Problem

[neng1996]

Hello,

Recently I turned on my stereo/turntable setup to find a humming/buzzing noise. Said noise was constant, unaffected by the volume control, and no music would come through when I played records on it. Even when I disconnected the speakers, there was still a faint crackling sound that can be heard coming from the receiver. My preliminary research indicated this might be a ground loop problem, so I checked all my inputs, switched around power outlets, etc. with no luck.

However, I discovered differences in the speaker inputs on the receiver while trying things out. There are four sets of speaker inputs on the back of the receiver. When I connect the speakers to the bottom two sets, I get the humming. When I connect the speakers to the top two sets, the humming somewhat goes away and music can be heard, albeit very distorted. Here's a picture of the speaker inputs for reference - https://image.ibb.co/fHGJ6S/Full_Size_Render.jpg

So where do I go from here? Is this a ground loop problem? Or is it a problem with my receiver, and in that case, is it an easy fix or will I need a new one? For reference, my (rather old) setup is a Fisher 143-92521600 Stereo Receiver, Fisher x5000 Speakers, and a Hitachi HT-354 turntable.
Thanks in advance.

 

[kanewolf]

You should use either the left side "A" or the right side "B". Not top/bottom. You may have an issue with the speaker selector switch. You might try switching them a dozen times.

 

[americanaudiophile]

A ground loop would still allow you to play music at normal volume but with the hum on top of it. You say you aren't getting any sound.
That receiver is old enough that the switches and controls might be the problem. WIth the receiver turned off operate each knob and control 20-30 times. They might need to be cleaned with the correct chemicals.
It might also have aged capacitors which would be much more expensive to repair. It would make more sense to replace it unless you have some attachment to it. A local tech should be able to diagnose the problem and clean the controls at a reasonable cost,