What was found
FUME EVENT DURING BLOCK IN RIGHT AFTER APU START. SEVERITY OVERWHELMING BURST OF ELECTRICAL BURNING ODOR. AFT GALLEY NO PHYSICAL EFFECT BY CREW OR PASSENGERS. NATURE ELECTRICAL. TIME 1753 LEVEL A DISSIPATES ON ITS OWN. T/S ODOR PER AMDS WC 0550-2001. USED P-TRACK TOOL TO ISOLATE SOURCE.OPERATED AFT GALLEY HEATER RECREATED ODOR. FOUND DEBRIS BUILD UP ON HEATER INTAKE VENT. REMOVED DEBRIS AND ODOR LEFT. UNABLE TO DUPLICATE ODOR AFTERWORDS. C/W AMDS WC 0550-2003 ODOR RTS TEST PASS. OK FOR SVC. (LP# 8902546; AIRCRAFT WAS GROUNDED)