Okay, I think I found the problem. I powered it up just now and took some more emitter resistor readings, there was a bigger gap in the Left channel than yesterday, 20mV/10mV, Right channel about the same as yesterday but I noticed that the reading taken from the resistors on the "left side" (see photo) of both Right and Left channels depended on where I placed the probe on the resistor lead. By physically manipulating the resistors, I could change the voltage readings and could get both emitter resistors of each channel to read 20mV/20mV.....😳
Would the tolerence make a difference, At 10% the resistors could either be 0.33 ohm or 0.27 ohm
Before I started this repair, I read the service manual and the suggested procedures for setting the bias seemed to be at two extremes. Setting the bias by measuring across the emitter resistors is the most direct way I assumed. Maybe there was a reason the engineers did not include it as an option.
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OPTION 2
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Good sleuthing!
Semms like replacing all four emitter resistors would be a good idea.
Semms like replacing all four emitter resistors would be a good idea.
One final thought--- you might add a bit of solder and flux to the joints on the terminal strips and reflow. Perhaps those joints have deteriorated with time and temperature.