So... As you might expect, both drivers were gone along with the thermal compensation transistor. Also 2 biasing resistors. With all that replaced, it lives again. I did replace the PNP driver as well, just so they "match", but it was okay.
I used TIP41C/42C for the outputs, a 2n3904 for the thermal comp. (with crossed B and C legs) and a pair of recovered TO127 transistors, which seemed closest to the specs required, for the drivers.
The amp is a Pioneer SA-420, if anyone's interested. Pretty basic, with loose biasing requirements of 2-100mV across the output emitter resistors according to the manual, and no adjustment pots. Both channels sit at about 25-30mV, I had to change R54 to 680 from 560 to achieve this. Then I gave the PCB and heatsink a good clean.
I used TIP41C/42C for the outputs, a 2n3904 for the thermal comp. (with crossed B and C legs) and a pair of recovered TO127 transistors, which seemed closest to the specs required, for the drivers.
The amp is a Pioneer SA-420, if anyone's interested. Pretty basic, with loose biasing requirements of 2-100mV across the output emitter resistors according to the manual, and no adjustment pots. Both channels sit at about 25-30mV, I had to change R54 to 680 from 560 to achieve this. Then I gave the PCB and heatsink a good clean.
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