As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) CENTER CARGO LT SIDE CIRCUIT BREAKER ON CONTROL RELAY BOX ASSEMBLY POPPED WHEN RESELECTED (PUSHED IN), SPARKS OCCURRED INSIDE OF THE CONTROL RELAY BOX NEAR LOWER CONNECTOR PLUG. THE CONTROL RELAY BOX ASSEMBLY WAS FOUND AT FAULT. PART WAS REPLACED AND THE AIRCRAFT WAS SENT BACK TO SERVICE.