Pioneer SA3000 idle current issue...help

[Leiff]

After having repaired the right channel due to a tremendous melting of the output transistors and drivers, and some pasive elements, I was able to have the voltages requested by the service manual.
in Q14 emitter 38v collector 1.18v and base of Q18 1.18 and the same for Q12 but in negatives.
It is sounding good, I have tested it with a bulb in series, after 15 minutes the heat sinks of the right side begin to heat up, when I measure between TP1 and TP2 the millivolts rise from 110mv constantly, I have reached 165mv and I turn off the amplifier, according to the manual it should be between 9.6mv and 66mv, I have no idea where the fault is, i have been used for the output transistors: 2sc2579 and 2sa1106, I need help to fix it
thanks

 

[Leiff]

In Q2 a have 0.008v and Q4 =0.04v both should be +0.6 and -0.6v resp.

 

[Leiff]

I dont understand... in left channel (good channel) i measure similar values?¡, the left channel stay cold as ice.... no matter how much time is turned on, while the right channel (repaired) littel by little goes warming while the voltage between TP1 and TP2 gradually increases in value reaching up to 161 mv, the amplifier is working, sounds with out distortion.... What usually causes this? a bad transistor? a bad diode? bad resistance? a bad capacitor?
I hope someone from the forum with an experience like this can help me and it doesn't become a monologue... still no one helps me...

 

[dcmeigs]

It always helps if you post a link to the schematic.

 

[dcmeigs]

 

[Leiff]

It always helps if you post a link to the schematic.

thanks for reply¡....i tried to attach the pdf in a good resolution, but its too big for the plataform. Do you have any idea about pionner´s issue ?

 

[Leiff]

 

[Leiff]

I measured these components and this is that i got:
Across R64 = -0.52v constantly
Collector Q12 to collector Q14 +2.38 constantly
D6 -0.70 constantly
D8 -1.65 constantly

Across R68=0.000v

 

[crnmd]

did you resolve this? I have one also