I have no line out signal from either left or right channel. I am currently using headphone output which seems ok. I wonder if another user has connected line out to amp mic input with 48v phantom power and damaged output driver? I haven't dismantled at all yet as keyboard in constant use so was hoping someone could advise best way to dismantle and which components are most likely to be faulty so I'm not going in "blind". It may be another cause but don't know. I take it that issue must be near output stage as presumably headphone output and line output have similar source? Any advice / circuit diagram / troubleshooting guide would be much appreciated. Thanks. Angus.