What was found
PRYOR TO PUSHBACK AND DURING PAX BOARDING, SMOKE WAS OBSERVED IN FORWARD CABIN AREA. BOARDING WAS DISCONTINUED AND REMAINING PAX WERE DEPLANED. APU FEEDER CABLE DAMAGED IN FIRST CLASS FORWARD CABIN RIGHT SIDE OVERHEAD BIN AREA. CABLES BURNED DUE TO CHAFED WIRING. PLACARDED APU GENERATOR INOP, MEL 24-00-02. APU GENERATOR FEEDER CANNON PLUG DISCONNECTED AT APU FIRE WALL. REPAIRED FEEDER CABLE BY SPLICING IN A NEW SECTION OF WIRE IAW BOEING STANDARD WIRING PRACTICES MANUAL 20-30-13. OPS CHECK GOOD, MEL CLEARED.