What was found
SMELL OF SMOKE IN COCKPIT AFTER APPROX 1 HOUR AT FL400. AIRCRAFT RUN WITH FULL ELECTRICAL LOAD, NO SMELL/DEFECTS NOTED. RT & LT CB PANELS LOWERED TO INSPECT CB PANEL REAR, NO DEFECTS NOTED. FREON AIR CON UNIT RUN FOR OVER 30 MINUTES NO DEFECTS/SMELL NOTED. INSP OVERHEAD BLOWER AS PER 21-21-04, NO DEFECTS NOTED INSP DEFOG. FAN BLOWER PER 21-21-01 NO DEFECTS NOTED. REMOVED, INSP, & CLEANED COALESCER SOCK PER 21-70-00. NO ODOR NOTED. ACCOMP ENG RUN, RUN ACH FULL HOT / FULL COLD FOR OVER 45 MIN NO SMELL / DEFECTS NOTED. RAN OVERHEAD BLOWER / DEFOG FAN FOR OVER 30 MIN NO SMELL / DEFECTS NOTED. NO ODOR, NO SMOKE, NO DEFECTS NOTED AT THIS TIME. COULD NOT DUPLICATE WRITE UP ON GROUND.