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Marantz 1060 right channel distortion

Elwood said:
J705 37.1
J707 37.4
Click to expand...
I would have liked to have seen a difference of 1 to 1.4volt (ie 2 diode volt drops) between J705 and J707
however this will not cause the 0V at J721. I'd be tempted to replace H711, possible c-e failed open, service
manual has it as 2SA606. That substitutions list has 2N5416 as a suitable sub, need to confirm this is ok.
 
Regarding H711, I'd be inclined to try KSA1220 (Ft high?) however my substitution skills are poor.
The diode pack/J705, J707 is probably a red herring.

Suggest you wait on others for a sub for H711 2SA606.
 
mbz said:
Regarding H711, I'd be inclined to try KSA1220 (Ft high?) however my substitution skills are poor.
The diode pack/J705, J707 is probably a red herring.

Suggest you wait on others for a sub for H711 2SA606.
Click to expand...
I checked transistor , h711, test ok with MM...no open or shorted situation. Lot of what appears to be glue around it...see pic...could that cause short?
 

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No, Marantz glue isn't conductive. You can scrape it off if you want but it's unlikely to be an issue.

Your right amp channel is distorted but the left amp channel is fine, correct?

Rather than testing the transistors, just swap them side-to-side one by one until the distortion changes sides. If it refuses to change sides, then it's not a transistor issue.
 
Not sure if they used the problematic sony glue in the 1060.
The marantz gurus will know. Certainly clean it up, carefully
use acetone or board cleaner to soften then scrape off.

The problem for me is the 0V on J721/H002b

Ballpark,
H711e (approx J717) +36.7V
H711b (J705) 37.1V
H711c (J721) 0V

Looks like the b-e junction is reverse biased.
Might be caused by a low volt drop on diode pack H005.
With one probe on J705, other on J707, monitor voltage.
Like to see 1-1.4Vdc.
 
mbz said:
Not sure if they used the problematic sony glue in the 1060.
The marantz gurus will know. Certainly clean it up, carefully
use acetone or board cleaner to soften then scrape off.

The problem for me is the 0V on J721/H002b

Ballpark,
H711e (approx J717) +36.7V
H711b (J705) 37.1V
H711c (J721) 0V

Looks like the b-e junction is reverse biased.
Might be caused by a low volt drop on diode pack H005.
With one probe on J705, other on J707, monitor voltage.
Like to see 1-1.4Vdc.
Click to expand...
Ok,so I should put h711 back in and test voltage at j705 and j707? H005 is the little black diode that gets clamped to heat sink correct?
 
Correct.
One probe on each pin, use minnigrabber or similiar rather than probing pins.
Thinking the volt drop may be about 0.5Vdc causing H711b to be too high...
Just a thought, others welcome...
 
mbz said:
Not sure if they used the problematic sony glue in the 1060.
The marantz gurus will know. Certainly clean it up, carefully
use acetone or board cleaner to soften then scrape off.

The problem for me is the 0V on J721/H002b

Ballpark,
H711e (approx J717) +36.7V
H711b (J705) 37.1V
H711c (J721) 0V

Looks like the b-e junction is reverse biased.
Might be caused by a low volt drop on diode pack H005.
With one probe on J705, other on J707, monitor voltage.
Like to see 1-1.4Vdc.
Click to expand...
Well- soldered back in now both channels working...was intermittent before so I assume will come back, 1.4v now reading across j705 and j707.
 
1.4V is good, maybe the heat cycle from the soldering helped H711 a little. Give it a little time to fail then recheck
the voltages.
 
EastPoint said:
No, Marantz glue isn't conductive. You can scrape it off if you want but it's unlikely to be an issue.
Click to expand...

True, it is not conductive by it's self, but it becomes hygroscopic with age, water is conductive and also can cause corrosion.
I always remove it as best as I can.

Tom
 
mbz said:
1.4V is good, maybe the heat cycle from the soldering helped H711 a little. Give it a little time to fail then recheck
the voltages.
Click to expand...
Ok, it played a week last time fine and then quit...will see what happens. Will let you know what happens . Thanks for the help!
 
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