Thought I'd start from the 48V switch trying to locate the generator.
But multiplexed into the uP like all the other switches. Only 63V caps
are at the mic input and L&R outputs. Other end of the board is a DC/DC
type inductive core lump next to 6 pin SMD IF8CG but no info found on
that topcode.
The owner was concerned as to whether he'd done something stupid,
despite it failing mid-song. Does owner psychology mean he did something
stupid, soon before the failure?