The SD Convertible effects loop is supposed to return directly to the output stages, bypassing the volume and tone controls. It seems mine is affected by the tone and volumes settings so it must enter the circuit upstream of where it should be according to the schematic. I see no sign of a mod and the return coax goes behind the circuit board so I can't trace where it actually goes. It seems that removing the board will require much desoldering and detaching dozens of wires. Does anyone have experience repairing and accessing the circuit board?
Thanks!