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Marantz 2015 left channel out/right distorted

I'm betting they're fine.

Have all the tape monitor switch, speaker switches and selector switches had a couple good cleanings yet?
 
bryans12v said:
Have all the tape monitor switch, speaker switches and selector switches had a couple good cleanings yet?
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Everything has been de-oxit and work smooth and have no effect on the sound problems. A couple resistors have gotten hot enough to discolor the board and one transistor has discolored the board where the pins go through.

Right now I have four units in various states of completion, a 4230 that's waiting on 4 caps, a Model 24 that I just recapped and has no FM, a Optonica with basically the same issue as the 2015 waiting on a service manual, and the 2015 that is posted here. The 4230 parts will probably come tomorrow and I'll finish that one and go back to the 2015. Thanks for all the help and input! Rich
 
The 2SD315 transistors don't really have a great cross for the same style shape and size . I have used NTE175 as a replacement and they worked just fine. I prefer to look on auction sites /etc and find original tested 2SD315 s' because it is a bit of a hassle messing with the heat sink assembly. And I might as well do it once and leave out the doubt. Yes these transistors are soldered to the wires.There is no (just loosen two bolts and pull them out) . If you want to test them in place just unsolder the two leads (the body is the cathode) then you can hook up your Component Tester. I would first get the amp board all rebuilt (including the bad transistors and diodes if any) For the diodes just unsolder one end and test. Same for resistors. You can use your ohm meter for this. The two big .5ohm (?) resistors on the right side (channel) look toasty. They can change value or become open. Just unsolder one end of each and test. This can cause that distorted sound on the right side. If you are lucky the right side might be fine if you find one of these resistors bad. But at the same time something is causing these guys to get hot. Just my 3 cents !
 
Richs_Trains said:
Right now I have four units in various states of completion
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and probably can only finish the 4230 (just a re-cap) with my limited abilities. I might have a chance with the 2015 and 3205, but only with the help of AK. As lost as I am trying to work on the power amp boards, the tuners are just 'no man's land' for me. Thanks for the help!
 
Richs_Trains said:
Beamer, where can I find these, SM shows them as 3 watt 0.5 ohm and I don't seem to be able to locate them. I would like to change all four along the back. Thanks Rich
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You just need to test them. If they test good you don't need to replace them. I found some on Flea Bay they were 5 watt. You can use 5 watt .5ohms. Don't replace if there is no need to. Hang in there you will surprise yourself with your talent. I might have some left over not sure of the value or quantity but I won't be home for a week. I will let you know
 
There are some .5 ohm 3 watt resistors listed on flea bay. I just checked. The blue metal film .5ohm 3 watt 1% tolerance
 
Ok Beamer, I changed out that 220 ohm resistor that looked heated, open when tested, pulled the .5 ohm resistors along the back and 3 out of 4 are open, one is .5 ohm. Can I use a higher wattage and the same ohms in the spot? Randomly check some transstors using the instructions on AK with the diode setting on my DMM, they all seem okay. one thing I don't understand, in the 'how to' it says depending on NPN or PNP, determines where you place your leads and it goes through NPN but doesn't say what is different for PNP. Thanks for any help. Rich
 
You can go up in watts for the resistor if it will fit . There are 3 watt .5ohm available. The NPN and PNP transistors are different in design. If you look at the diagram in one of the previous posts you will see how that is. I use a component tester and it does the "thinking" for me. It also tells me which leads are Emitter, Base and Collector. As well as the Hfe (gain). I recommend you get one. Testing transistors is part of the learning curve.
 
According to Echowars post, testing PNP with a diode tester is the reverse of the NPN. Negative lead on base and positive on emitter or collector should read a diode drop. Positive on base and negative on E or C should read OL or no conduction.
 
Beamer, On the resistor, changing the wattage has what effect? lower voltage hotter? higher cooler? same effect on signal as long as the ohms are the same? Thanks Rich

Steven Tate said:
According to Echowars post, testing PNP with a diode tester is the reverse of the NPN. Negative lead on base and positive on emitter or collector should read a diode drop. Positive on base and negative on E or C should read OL or no conduction.
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Thanks Steven, will at to my cheat sheet!
 
If you have a 5 watt resistor it can handle more heat. (won't get as hot) The signal will be the same , These resistors are part of the protection circuit for the Output Transistors .
 
If these resistors tested open then the transistors need to be tested as well.They probably took a beating. H611 and H 613 on the right side and H612 and 614 on the left side.. H 615 and H617 (right side) and H616 andH618 on the left side. Transistors H611 and H613 (right side) and H612 and H614 (left side) are part of the protection circuit. (current limiters) I told you about in the previous post.
 
Replaced the bad transistor, bad resistor and put 4 3watt .5 ohm resistors across the back, when I powered it up on DBT and got a full bulb. Pulled the 4 resistors across the back and put it back on the DBT, no short. Does this mean my outputs are fried? Rich
 
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