eizner23
Super Member
Not completely out, i get a little sound out of it. Occurred after I heard a crackle and pop in the right channel. I hooked up a Dynaco preamp and the issue doesnt persist, so perhaps the receivers preamp is at fault.
Preamp board as rebuilt prior to the loss of sound, worked fine for over a year, only original parts in that board are the mylar caps and diodes.
I suspected bad transistor in preamp. Pulled them all out (KSC1845) and all tested fine. Replaced them anyways. Service manual doesnt really have many test point measurements for preamp circuit, so my diagnosing stopped there.
Gave the balance/vol pots a good deoxit faderlube cleaning, along with the Separate/Normal switch with D5 but the issue still persists. Rechecked the soldering, looks fine.
My question is what other circuits are in-line with the signal path that could be suspect? The tone circuit looks as if its bypassed when Bass/Treble knobs are switched to "Off" position, and I wonder if the low/high filter boards are bypassed when not engaged? I hope someone can confirm this for me or give a little help.
Preamp board as rebuilt prior to the loss of sound, worked fine for over a year, only original parts in that board are the mylar caps and diodes.
I suspected bad transistor in preamp. Pulled them all out (KSC1845) and all tested fine. Replaced them anyways. Service manual doesnt really have many test point measurements for preamp circuit, so my diagnosing stopped there.
Gave the balance/vol pots a good deoxit faderlube cleaning, along with the Separate/Normal switch with D5 but the issue still persists. Rechecked the soldering, looks fine.
My question is what other circuits are in-line with the signal path that could be suspect? The tone circuit looks as if its bypassed when Bass/Treble knobs are switched to "Off" position, and I wonder if the low/high filter boards are bypassed when not engaged? I hope someone can confirm this for me or give a little help.