i took out every semiconductor, and i went back as far as taking out of the board q202, q203, q204 and q 205.
all semiconductor checked ok, and no voltage at the output up to this point, but it is kind of difficult to trace back from here.
are q601, and q602 part of what i need to check?
I pulled out all semis from the board and tested them. And while I pulled them out of the circuit ( by sets ) I tested for voltage at the output and there was no voltage at the speakers terminals.
I also pulled out Q601 and Q602 and there was voltage at the speakers terminals.
Both transistors checkered Ok.
About Q201, I don’t see it on this board.
i found this schematic on the web, the components location numbers match on a 95%, i was able to confirm that the pre amp for both channels are working fine, and it looks like the driver circuit is the problem, however, except for the output transistors, i exchanged all driver circuit components from the good channel to the bad one and vice versa, and the problem remains on the bad channel. i also noticed that the bad channel have a square wave at its output, instead of audio signal. the output filter composed of c190 and r296 is working ok