What was found
SEA BTB NON-ROUTINE LINE CHECK-SPARKS AND SMOKE NOTED COMING FROM OVERHEAD GRILL BETWEEN L1 DOOR AND FORWARD GALLEY. INSP REVEALED THAT A WIRE BUNDLE WAS CHAFING ON A PLENUM DUCT CLAMP, SOME OF THE WIRING WAS SHORTING ON CLAMP, AND HAD BURNED THROUGH 1 FOOT FORWARD OF S3-25 TERMINAL STRIP. IT WAS FURTHER DETERMINED THAT THE WIRING BUNDLE HAD BEEN MIS-ROUTED, AND DUCT CLAMP HAD BEEN IMPROPERLY INSTALLED. REPAIRED DAMAGED WIRING. REROUTED WIRING BUNDLE, ALSO REPLACED PLENUM DUCT AND CLAMP. OPS CHECKED OK.