Mrantz SR6008 - Front Left Channel Gradual Signal Loss

[hopperwelles]

Hello,

I have gotten no response from subreddits, over the past few months - so I figured I would ask here.

I have had a Marantz SR-6008 for maybe eight years now - it’s a really solid receiver that fits my setup well and works for my apartment. However, the front left channel will fluctuate where the signal gets very faint for several days - months even, then without warning, it’s back to full strength. The last time i brought it to get repaired the issue could not be replicated (I still paid a boatload for their time however). I’m tired of spending money on this unit. Before you ask, I have tested the speakers by switching inputs, and it is not the speakers themselves but the front left input itself. I use banana plugs for my speakers - would i have better luck going straight into the unit? Apparently, this is a phenomena that others have experienced as well.

Can anyone help me out here? Thanks in advance.

 

[TLS Guy]

Hello,

I have gotten no response from subreddits, over the past few months - so I figured I would ask here.

I have had a Marantz SR-6008 for maybe eight years now - it’s a really solid receiver that fits my setup well and works for my apartment. However, the front left channel will fluctuate where the signal gets very faint for several days - months even, then without warning, it’s back to full strength. The last time i brought it to get repaired the issue could not be replicated (I still paid a boatload for their time however). I’m tired of spending money on this unit. Before you ask, I have tested the speakers by switching inputs, and it is not the speakers themselves but the front left input itself. I use banana plugs for my speakers - would i have better luck going straight into the unit? Apparently, this is a phenomena that others have experienced as well.

Can anyone help me out here? Thanks in advance.

You questions as posed do not make much sense. I suspect you mean you switched outputs and not inputs. In other words you swapped the right and left speaker leads at speaker outputs. Is that correct?

You do not say whether you have switched inputs. You would need to use analog RCA inputs to test this.

I have no idea what you mean by going straight to the receiver. That means zero to me.

So the speakers are eliminated as the cause.

So you need to switch inputs from an analog sending device, and see if the fault always stays with the left speaker, when you switch left and right inputs. If it stays on the left speaker then the receiver has a problem, that you won't fix, and at that age, likely no one else will either, not at a realistic cost anyway.

 

[hopperwelles]

You questions as posed do not make much sense. I suspect you mean you switched outputs and not inputs. In other words you swapped the right and left speaker leads at speaker outputs. Is that correct?

You do not say whether you have switched inputs. You would need to use analog RCA inputs to test this.

I have no idea what you mean by going straight to the receiver. That means zero to me.

So the speakers are eliminated as the cause.

So you need to switch inputs from an analog sending device, and see if the fault always stays with the left speaker, when you switch left and right inputs. If it stays on the left speaker then the receiver has a problem, that you won't fix, and at that age, likely no one else will either, not at a realistic cost anyway.

Thanks for responding so quickly!

Let me be as specific as possible, so there is no possibility for confusion. I have a 5.0 speaker setup at present. Front Left, Center, Front Right, Surround Left, Surround Right and a Subwoofer. The fault appears to emanate from the front left speaker +/- terminals only. All other terminals work fine. I am asking what steps, if any, can be done to figure out why the problem keeps reoccurring.

By "straight into the receiver" I was trying to eliminate the banana plug as possible culprits. That is, to forgo banana plugs and insert the speaker wire directly into the terminals.

 

[TLS Guy]

Thanks for responding so quickly!

Let me be as specific as possible, so there is no possibility for confusion. I have a 5.0 speaker setup at present. Front Left, Center, Front Right, Surround Left, Surround Right and a Subwoofer. The fault appears to emanate from the front left speaker +/- terminals only. All other terminals work fine. I am asking what steps, if any, can be done to figure out why the problem keeps reoccurring.

By "straight into the receiver" I was trying to eliminate the banana plug as possible culprits. That is, to forgo banana plugs and insert the speaker wire directly into the terminals.

There is still confusion. Does this happen on all inputs for a start? You need to swap a right and left analog input to really pin this on the receiver.
It is not going to be the banana plugs unless the screws are loose and then the wires would fall out. So it a waste of time looking there.

I have to say this most likely is a problem with the receiver. Unless you are an experienced service technician with test equipment I doubt you will solve it.

The only thing you could try is a reset back to factory defaults, and I would definitely do that, once you are certain it is the receiver.

Just make a record of all your settings before you do it.

Since this fault is intermittent, I doubt a reset will solve it, but you never know.

If a reset and re-set up does not solve it then you probably need to cut your losses and replace the receiver.

 

[hopperwelles]

There is still confusion. Does this happen on all inputs for a start? You need to swap a right and left analog input to really pin this on the receiver.
It is not going to be the banana plugs unless the screws are loose and then the wires would fall out. So it a waste of time looking there.

I have to say this most likely is a problem with the receiver. Unless you are an experienced service technician with test equipment I doubt you will solve it.

The only thing you could try is a reset back to factory defaults, and I would definitely do that, once you are certain it is the receiver.

Just make a record of all your settings before you do it.

Since this fault is intermittent, I doubt a reset will solve it, but you never know.

If a reset and re-set up does not solve it then you probably need to cut your losses and replace the receiver.

The issue only occurs on the front left channel, regardless of signal (analog or hdmi). All other inputs work nominally and have been tested. I will do a factory reset and write back once ive established whether it solves the issue.

 

[TLS Guy]

The issue only occurs on the front left channel, regardless of signal (analog or hdmi). All other inputs work nominally and have been tested. I will do a factory reset and write back once ive established whether it solves the issue.

See if a hard reset solves it. If it does it on analog and HDMI inputs there probably is a receiver problem.

If a reset, and try up to three, does not solve it, then open the unit after acquiring a can of Deoxit.
Carefully remove each ribbon connector one at a time and spray a SMALL amount of Deoxit on the male and female ends. Make sure all boards are properly seated.

If that does not solve it, then recycle the unit or advertize it on eBay, as not working and for parts or repair. A tech might buy it and scavenge boards of it.
It would probably fetch $30.00 to $50.00.

I do find it odd that the tech that had it did not detect a fault if this unit malfunctions as often as you say. That is why I'm concerned the problem is external to this unit somehow.

 

[PENG]

The issue only occurs on the front left channel, regardless of signal (analog or hdmi). All other inputs work nominally and have been tested.

This is not clear, seems contradictory too. If you say regardless of signal, analog or hdmi, and then you say all other inputs work nominally (note: nominally means they work okay?), so which input caused the left channel to faint?

Once you make this point crystal clear, then we can suggest some troubleshooting steps to narrow down the probable trouble spot. Until then, you can even say the AVR is the problem, though as TLSGuy suggested that it was likely the case.

Even if the AVR is the issue, it is worth to find out if it is the power amp section of the preamp/processor section, and that one is easy to determine. If the power amp section is the issue, then even if you don't want to send it out for repair, you can still use that one channel with a cheap external amp, such as a $80 class D amp, that should perform better than the SR6008's internal amp in terms of distortions and noise.

I will do a factory reset and write back once ive established whether it solves the issue.

Yes, that is a necessary step, as it may fix it, depending on the cause(s) of the issue.