What was found
(CAN) UPON GETTING IN A/C DISCOVERED AC POWER C/B`S POPPED UPON EXTERNAL PLUGGED INTO A/C ASSUME POPPED WHEN GSE PLUGGED IN PILOT ENTERED COCKPIT AND PUSHED ALL BREAKERS IN ON WALK AROUND EXITING A/C AND DOING WALKAROUND WENT BACK TO COCKPIT AND DISCOVERED SMOKE REMOVED POWER FROM A/C AND CALL MAINTENANCE UPON REMOVAL OF AC POWER MONITOR DISCOVERED BURNED CONNECTOR ON INDICATOR AND CONNECTOR, CONNECTOR AND INDICATOR /MONITOR REPLACED WITH NO FURTHER ISSUES.