What was found
F/A'S REPORTED AN ODOR RESEMBLING BURNING RUBBER NEAR 3B/A. CALLED MAINTENANCE & DISPATCH AND RETURNED TO DEPARTURE. HAD JUST REACHED CRUISE ALTITUDE WHEN FA CALLED. COMPLIED WITH AIR CONTAMINATION CHECKLIST M-744 ODOR WAS LOCALIZED AT SEAT 3AB AND ADJACENT AISLE, WAS NOT ASSOCIATED WITH AIR CONDITIONING, INSPECTED ALL READING LIGHTS, SIDEWALL & OVERHEAD LIGHTS AND BALLASTS FROM ROW 1AB TO ROW 4AB-NO ODORS OR DEFECTS FOUND. RETURNED TO SERVICE.