What was found
DFW - FLT 1738 - EN ROUTE DTW/DFW DURING CRUISE, ODOR SIMILAR TO HOT PLASTIC NOTED IN CABIN. NO OTHER ABNORMAL INDICATIONS AND AIRCRAFT PROCEEDED TO DFW LANDING WITHOUT INCIDENT. REPLACED PASSENGER SERVICE UNIT PANEL AT SEAT 5DE DUE TO RELAY FOUND HOT AND MELTING. SYSTEM GROUND CHECKED, NORMAL OPERATION. (X)