What was found
NOTED ELECTRICAL BURNING ODOR JUST BEFORE START. ALSO, NOTED POSSIBLE SMOKE FROM THE SEAT ROW 1 AREA. SHUTDOWN AND CALLED CFR. EVACUATED THE AIRCRAFT. ODOR AND SMOKE NEAR SEAT 1D, ALLS FANS, SUPP A/C AND POWER WAS TURNED OFF, SMOKE STOPPED. REPLACED LEFT RECIRC FAN.