As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IN CRZ F/A SELECTED LWR LVL SWITCH ON N52 CART CTRL PANEL AND IT SPARKED. BREAKER POPPED CREW REPORT THAT FLT ATTNS NOTICED ARCING FROM THE TECH CART CONTROLLER ON N52 WHEN SELECTD ON. THE CIRCUIT BREAKER POPPED AND AN ACRID ELECTRICAL ODOR NOTICED. THE CONTROLLER WAS ISOLATED AND ALSO N51 AND NO FURTHER PROBLEMS NOTED.