What was found
WINDSHIELD 1 HTR FAIL CAUTION MSG. RETURN TO FIELD. LANDING UNEVENTFUL. PLACED ON MEL. MEL CLEARED BY C/W E175 FIM 30-42-00-810-801-A FOR FAULT CODE 30420028AI1, REMOVED AND REPLACED #1 SPADA I/O MODULE SLOT 19 PER AMM 24-61-05-000-801-A, 24-61-05-400-801-A AS A PRECAUTIONARY, NO HELP. VERIFIED L/H WINDSHIELD HEATING ELEMENT AND TEMP SENSORS PER CMM 56-10-01, CHECKED GOOD. SWAPPED L/H AND R/H WINDSHIELD HEAT CONTROLLERS, FAULT FOLLOWED TO R/H SIDE, SWAPPED BACK TO ORIGINAL POSITIONS AND REPLACED L/H CONTROLLER PER AMM 30-42-01-000-801-A, 30-42-01-400-801-A, OP TEST GOOD, PLACARDS REMOVED, NO CB'S OUT, CLEAR MEL. RETURNED TO SERVICE.