What was found
(CAN) AIRCRAFT REPORTED HAVING A CIRCUIT BREAKER POP FOR THE VIDEO SYSTEM IN ZONE ``D`` FOUND OPEN CIRCUIT WIRING AND BURNED SHIELDED WIRES BETWEEN VDU 6 AND VDU 7 IN THE AFT ACFT CABIN. CAUSE OF THE DAMAGED WIRING WAS A FAILURE OF THE AIR CONDITIONING DUCT SUPPORTING BRACKET. THE BROKEN BRACKET HAD MIGRATED OUTBOARD AND CHAFED THE WIRING AND THE 115VAC SUPPLY WIRE CONDUCTOR WAS ALSO CONTACTED. THE BROKEN BRACKET ALSO CONTACTED THE ADJACENT GASPER DUCT AND CHAFED A 1.5 INCH CUT INTO THE 3.0 INCH GASPER DUCT.THE LOCATION OF THE BRACKET AND AREA OF DAMAGE TO THE WIRING AND GASPER DUCT IS STA 1220 , WL 300, LBL 15.