What was found
F/A REPORTED AN ELECTRICAL BURNING ODOR NEAR SEATS 19, 20 AND 21. TURNED OFF CABIN LIGHTS IAW QRH. ODOR DISSIPATED. MX INSPECTED AREA SURROUNDING SEATS 19, 20 AND 21. NO DEFECTS NOTED. CONTINUED TROUBLESHOOTING AND FOUND LINE TO AUXILIARY WATER PRESSURE PUMP AIR SUPPLY LINE BLOWN OFF AND MELTED. R & R AUXILIARY PUMP AND SUPPLY LINE. NO HELP. APPLIED MEL 38-10-01A. 30JUL MX CONTINUED TROUBLESHOOTING AND FOUND AIR PRESSURE SWITCH S1545 BAD. R & R SAME. OPS CHECKS GOOD. MCO/PLAC REMOVED.