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Marantz 2015 left channel out/right distorted

Richs_Trains

Richs_Trains

Well-Known Member
Hey guys,

Got another 2015 to try to revive. This one came in pretty bad shape, very dirty, dial string off and audio problems. I hooked it up on the DBT and there is no short. Audio wise, the left channel appears dead and the right is distorted at any kind of volume. I did some beginning work in replacing the dial lamps, velum and re-capping the power supply. The the amp board large caps (I think they are 2200uf 35v, already closed it up, so can't readily check) are swollen on the tops as is the large filter cap. I ordered the caps for the power amp and was hoping for some insight as to the audio problems I am experiencing while I am waiting on Mouser. What would be the easiest to check with a DVM. Thanks for any help!! Rich
 
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On the amp board look for burned or toasted resistors, especially the four big ones on the back edge of the board near the heatsink. They tend to darken with too much heat or just become open. If you find burned or open resistors you will have other components that caused it.
check voltages and compare to schematic. I love that model Marantz I have 5 of them. Good luck.
 
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Visual inspection of the amp board show heat at R640, R642, R651 and H616. R640 and H616 show the most with discoloration of the wafer board where the pins go through, none are actually burned up I am not able to adjust the bias below 18mv on either channel, spec is 7.5mv. R-647-650, resistors on back) have gotten hot as the writing has faded off and you can see the impression of the winding in the center of the resistor, but no discoloration of the board or the resistor. This one may be too far gone for me. Thanks for any help, Rich
 
Looks like you might have to get some more parts from Mouser. The heat is coming from bad transistors and some out of value capacitors. To get to the underside of the board I unsolder the four front wires and unscrew the ground strap. Unscrew the four corner screws and then you can lift up the board . Leaving the back wires connected. If the dial cord is already unlaced then you are better off leaving it that way for now ( I have a habit of burning the cord with the soldering iron) Having a good desoldering iron a great thing. I use a Hakko FR300. I would work on just one side at a time (left channel or right channel ) To check the outputs it is better to desolder the wires going to them.To get them out of circuit. They are a bear the pull out of the heatsink . You might want to get an Atlas Component Analyzer made by Peak for testing diodes and transistors. As you move through the process use your DBT and you might want to try using your headphones (they only work from the preamp) You might want to try that now just to hear if it is different than using speaker. It is all doable you have the talent . The big resistors that look toasty may be out of value. The board is split down the middle left and right. You can compare ohm readings on the left then see what the right side is . Carry on !
 
Thanks Beamer, ordered the caps for the board from Mouser and the resistors and transistors from our local supply house. I had to get NTE because I couldn't figure out how to cross them to anything else ( seems NTE are not very well liked on AK). The large caps are all swollen and you can push on the tops. Biggest problem for me is that you have to unsolder the board and then reconnect it to see if you have made progress. I think I am going to extend the wires temporarily while I am working on it. I love these units also, this is my third 2015. Thanks again for the help, Rich
 
Here are some cross reference for P600 Amp Board.
H611 and H612 (2SC828A) use KSC1845FTA
H613 and H614 (2SA564A) use KSA992FTA
H615 and H616 (2SC1384) use KSC2690AYS
H617 and 618 (2SA684 use KSA1220AYS
some of these might have a different pin out than original
 
Tried with headphones, exactly the same.... no left channel and right channel distorts with any volume. Where does that point?
 
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Richs_Trains said:
Tried with headphones, exactly the same.... no left channel and right channel distorts with any volume. Where does that point?
Click to expand...
Probably the Amp issues. If you took the Output transistors out of circuit you might notice a change. At least test the output transistors so you know their condition while you are waiting for your parts.
 
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I just had another thought. What are you using for an audio signal? If it is the FM tuner ...hummmmm...better to use something you can plug into the AUX input just to rule out AM/FM board issues if any.
 
Using an outboard tuner connected to aux. re-capped what I had on the shelf, need the big caps and the other components. pics...

2015c_1.jpg 2015c_2.jpg 2015c_3.jpg 2015c_4.jpg

Thanks Rich
 
Beamer302 said:
If you took the Output transistors out of circuit you might notice a change. At least test the output transistors so you know their condition while you are waiting for your parts.
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I don't know how to test them, never actually pulled outputs before. And also, the headphone jack disenegrated in my hands, ordered another. Rich
 
Richs_Trains said:
I don't know how to test them, never actually pulled outputs before. And also, the headphone jack disenegrated in my hands, ordered another. Rich
Click to expand...

I don't think your outputs transistors would be the problem. My bet is on a dirty switch or pot.


To test the outputs just pull the two screws and pull them right out assuming they're to-3, to-66 packages I believe the output on the 2015 is quasi complementary using all NPN in a TO-66 package which may be very hard to find. Drivers may be NPN/PNP. When testing the first thing to do is figure out if they're NPN or PNP. Then use this chart.

index.jpg

For a better understanding read this thread.

http://audiokarma.org/forums/index.php?threads/bipolar-junction-transistor-testing-basics.43186/

Also remember that while it's a good measure if they are bad or not, this will not tell you if they are leaky. These will sometimes test fine until they're in circuit and on, then be problematic. This will also not provide you with any gain specifications which can be a VERY important specification. My advice would be to buy one of those cheap component testers off that auction site. Most likely made in HK, they work pretty good for about 20 bucks! Having this you'll at least be able to gain match different pairs also. Or, you could spring for a better built unit for about 60 bucks shipped.

I see you've been bit by the Marantz bug also! :beerchug:
 
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I am assuming from the SM the outputs are H001-H004 2SD315, which crosses to an NTE 175, what is the better choice.
bryans12v said:
ust pull the two screws and pull them right out assuming they're to-3, to-66. I believe the output on the 2015 is quasi complementary using all NPN. Drivers may be NPN/PNP. When testing the first thing to do is figure out if they're NPN or PNP. Then use this chart.
Click to expand...
These have two pins and I am guessing a ground on the case and look to be soldered in place.
2015c_5.jpg 2015c_6.jpg

and the hot spot:
2015c_6.jpg
 

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Call me silly , but I like the look of Nichicon caps, something about looking through the vents and seeing those gold and blue caps pleases me. I know everyone is high on all these different caps for different applications, but I just replace value for value with a good quality (nichicon) cap. I know how to solder and un-solder, but not much else. So I basically hope I get a working unit that I can 'refresh', sometimes I get one like this and I need lots of help! Thanks Rich
 
Richs_Trains said:
Call me silly , but I like the look of Nichicon caps, something about looking through the vents and seeing those gold and blue caps pleases me. I know everyone is high on all these different caps for different applications, but I just replace value for value with a good quality (nichicon) cap. I know how to solder and un-solder, but not much else. So I basically hope I get a working unit that I can 'refresh', sometimes I get one like this and I need lots of help! Thanks Rich
Click to expand...
i love nichicon. my OCD goes nuts when i plan a recap job because i will spend literally 3 hours thinking "what series do i want to use" just for the color of them. FG, KW, KA, ES, oh man...
 
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