What was found
HOT ELECTRICAL INSULATION ODOR COMING FROM SEAT 5 WINDOW (3RD WINDOW AFT MAIN CABIN DOOR), BECOMING STRONGER AFTER A FEW MINUTES PROMPTING ACFT SHUTDOWN. OPERATIONAL CHECK OF LIGHTS, SHADES, OUTLETS AND ELECTRICAL EQUIPMENT GOOD. NO NOTICEABLE BURNING ODOR. RAN AIRCRAFT APU AND ENVIRONMENTAL SYSTEMS. NO FAULTS HOT OR COLD. AIRCRAFT GOOD FOR CONTINUED SERVICE. OPERATIONAL CHECKS IAW IMM, CABIN MANAGEMENT MANUAL, MM 33-20-00 AND 49-10-00 AND 21-11-00.