What was found
FA.S NOTED BURNING ODOR MID CABIN. FLOOR IS HOT TO THE TOUCH. VERIFIED CRACK ON VALVE NO OTHER DEFECTS AROUND SURROUNDING AREA. BEGUN REMOVING APU BLEED VALVE PER B737 AMM 36-13. INSTALLED APU PNEUMATIC DUCT AND TIGHTENING V-CLAMPS PER B737 AMM 36-13. PERFORMED LEAK TEST PER 36-13-01 TEST GOOD. REINSTALLED AFT CARGO,FWD, CENTER &RH PANELS B737 AMM 25-52. RESECURED PANELS PERFORM LEAK CHECK OF PNEMATIC PRESSURE SEAL PER B737 AMM 36-13. OPS CHECKS GOOD. (LOG 8876426 - AIRCRAFT WAS GROUNDED).