Pioneer RX-570 Imbalance

Does anyone have any ideas on what could cause an imbalance in my Pioneer RX-570? The speakers are Marsland/ Leigh, and 6 ohm approx. The stereo was given to me in working order, I've just added my speakers. It sat for several years though.

When I dial the balance knob to the left position (approx 80% turned) , it sounds even side to side. When the knob is in the neutral detent, the left speaker is silent.

Does anyone have the service manual?
 

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These all-in-one music systems were very popular back in the 80's and 90's but finding a manual might be problematic.

I think you might just have to dive in and do some basic fault finding. Begin by looking at the signal on the 'top' end of the volume control. Make sure it is all inputs that are faulty and not just one.
 
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These all-in-one music systems were very popular back in the 80's and 90's but finding a manual might be problematic.

I think you might just have to dive in and do some basic fault finding. Begin by looking at the signal on the 'top' end of the volume control. Make sure it is all inputs that are faulty and not just one.
Fair enough and Thank you. This system was a way for me to enjoy music while I'm finishing up my DIYA Badger build. I've been "slumming it" with a compact system for years now...
 
Nothing lost in having a look inside. Could it have sustained physical damage over the years and have cracked print somewhere perhaps if the balance or volume controls got a whack.
Could it likely be the speakers? They do seem to match up with turni g the dial, so I just assumed they were OK.

I'm not the most experienced with load sharing speakers and such.

I'll definetly poke around when I have some free time.
 
Speakers are easy to prove, just swap the left and right connections around at the back of the amp and see if the imbalance transfers to the other speaker (meaning the amp is at fault) or remains the same (in which case the speaker is faulty).

You can also connect both speakers in parallel to one channel as a test (don't turn it up very loud if you do this) and you should get perfect mono at the same level from each speaker as each is fed with an identical signal.
 
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Speakers are easy to prove, just swap the left and right connections around at the back of the amp and see if the imbalance transfers to the other speaker (meaning the amp is at fault) or remains the same (in which case the speaker is faulty).

You can also connect both speakers in parallel to one channel as a test (don't turn it up very loud if you do this) and you should get perfect mono at the same level from each speaker as each is fed with an identical signal.
Thank you! That's a great T/S step. I appreciate the help Mooly.
 
Swapped speakers Channel to channel, and the problem followed. It seems to get worse if I wiggle the volume pot (externally). I guess I'll open it up and try to clean/ inspect the pot(not sure what they use in stereos, but many pots are cleanable on the aircraft's I work on).

Would it be I'll advised to plug the main speakers into the rear speaker connection Jack's? , or center for that matter? I'm curious if it's just a problem with one channel or many.
 
It seems to get worse if I wiggle the volume pot (externally).
That obviously shouldn't be happening and so it suggests a problem either with the pot itself or perhaps the soldering of it. Many pots are of an 'open' type construction that makes it easier to attempt a clean of them.

Would it be I'll advised to plug the main speakers into the rear speaker connection Jack's? , or center for that matter? I'm curious if it's just a problem with one channel or many.
I can't see any issue doing that.
 
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