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New to me Marantz 2275 (with issues)

You may have to do some signal tracing to find out what’s going on. If you don’t have an audio signal generator and scope, you can use a phone app to inject a sine wave into the aux inputs and then measure AC mV in and out of preamp, and into amp board to see where you are losing signal. The symptoms are so confusing, I can’t tell where the problem is. But it’s beginning to sound more like preamp than amp. There is a big connector on the PE01 preamp board that can cause these problems if the contacts are wonky. I would pull that connector off and clean with Deoxit, and put it back to see if anything changes. Otherwise, it’s signal tracing.
 
Steven Tate said:
You may have to do some signal tracing to find out what’s going on. If you don’t have an audio signal generator and scope, you can use a phone app to inject a sine wave into the aux inputs and then measure AC mV in and out of preamp, and into amp board to see where you are losing signal. The symptoms are so confusing, I can’t tell where the problem is. But it’s beginning to sound more like preamp than amp. There is a big connector on the PE01 preamp board that can cause these problems if the contacts are wonky. I would pull that connector off and clean with Deoxit, and put it back to see if anything changes. Otherwise, it’s signal tracing.
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Signal tracing it is LOL .. damnit... this things putting up a fight but its dinner time.. will report back tomorrow with some more info hopefully. Thank you for your immense amount of help I truly appreciate it
 
Have you given even a passing thought :idea: about cleaning the pots and switches before starting all this "recapping" to "fix" an issue? Recapping rarely, if ever, "fixes" a dead channel...
 
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Skywatcher said:
Have you given even a passing thought :idea: about cleaning the pots and switches before starting all this "recapping" to "fix" an issue? Recapping rarely, if ever, "fixes" a dead channel...
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Yes a full cleaning was performed prior to me doing anything on the unit. All the switches pots etc were removed cleaned and then reinstalled. The unit would only light up when I first got it. Cleaning it brought back the left channel, and free’d the controls / button of static. I ordered a recap kit for the PE01 preamp board
 
Take an RCA cable and connect one end to the Right Pre-Out, and the other end to the Left Main-In and see what happens. Then with the cable still like that, connect the Left Pre-out to Right Main-in and see what happens. Your balance knob will just work opposite L/R.
 
Skywatcher said:
Take an RCA cable and connect one end to the Right Pre-Out, and the other end to the Left Main-In and see what happens. Then with the cable still like that, connect the Left Pre-out to Right Main-in and see what happens. Your balance knob will just work opposite L/R.
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so criss crossing the jumpers ? Will do. Will report back shortly
 
Skywatcher said:
Take an RCA cable and connect one end to the Right Pre-Out, and the other end to the Left Main-In and see what happens. Then with the cable still like that, connect the Left Pre-out to Right Main-in and see what happens. Your balance knob will just work opposite L/R.
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Okay tested with the RCA wires placed in the position you told me. Still getting only left channel, sound is clear and adjustable via volume knob at all listening levels
 

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Skywatcher said:
Take an RCA cable and connect one end to the Right Pre-Out, and the other end to the Left Main-In and see what happens. Then with the cable still like that, connect the Left Pre-out to Right Main-in and see what happens. Your balance knob will just work opposite L/R.
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looking closer I see that the left and board has a ground to the chassis and then looking at the right and board I do not see the same ground wire is that supposed to be this way? From the J710 connector theres only 2 wires while theres 3 wires on the left J710 ?
 

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Are there any other black ground straps directly from the amp board to chassis? I expect the board should have one, but the other black wire on that connector does provide ground. So, I would think it would work anyway. But I don’t have one to compare to.
 
Steven Tate said:
Are there any other black ground straps directly from the amp board to chassis? I expect the board should have one, but the other black wire on that connector does provide ground. So, I would think it would work anyway. But I don’t have one to compare to.
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from another AK post. Looks like its fine. Still something else as far as what the culprit is
 

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xalara76 said:
It worked but seemed to only play when volume knob was turned half way and up
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And when you criss crossed the RCA's, the left side worked properly either way, but the right side not? If so, that right amp is bad, and it becomes a matter of finding the bad components.
 
Steven Tate said:
And when you criss crossed the RCA's, the left side worked properly either way, but the right side not? If so, that right amp is bad, and it becomes a matter of finding the bad components.
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left side on right worked but still only played via left channel of speaker. I think I can conclude this is a preamp problem.
 
Geez. I am staying lost on this. If you criss cross the RCA cables, and leave everything else the same, if the bad channel stays on the same side, it is an amp problem. If the bad channel swaps sides, it is a preamp problem. So which is it?
 
I'm going to have to test again with swapping amp boards on opposite sides and report back. I honestly forgot from everything going on yesterday. Please bare with me. I apologize. Will write down with test results after dinner and get back to you.
 
You really shouldn't have to swap the amp boards. That is a valid test, but the RCA swap is easier and tells you if it is preamp or amp.
 
xalara76 said:
I'm going to have to test again with swapping amp boards on opposite sides and report back. I honestly forgot from everything going on yesterday. Please bare with me. I apologize. Will write down with test results after dinner and get back to you.
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Just swap the cables like I said! :rolleyes:
 
xalara76 said:
Okay tested with the RCA wires placed in the position you told me. Still getting only left channel, sound is clear and adjustable via volume knob at all listening levels
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One side at a time. What was the result? Then both like I said. What was the result? Balance all the way to the left will actually be the right channel. If it works, it's not the preamp's right channel. Balance all the way to the right will be the left amp.
 
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