As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE WORKING INBD WRITE UP, DETECTED SMOKE IN COCKPIT. LOOKED TO CIRCUIT BREAKER PANEL 131VU SAW FLICKER OF FLAME FROM BEHIND PANEL. OPEN PANEL AND EXTINGUISHED FLAMES. INSTALLED NEW APU START CONTACTOR 5KA. DAMAGED CONTACTOR 5KA MANUFACTURER INTERTECHNIQUE SA. APU START NORMAL IAW MM 49-10-00-05 AND JRH.