As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT NR 3785 ENROUTE, REPORTED THE DUCT TEMPERATURE WOULD NOT GO BELOW 55 DEGREES. DURING GROUND OPERATION THE TEMPERATURE WOULD NOT GO BELOW 70 DEGREES WITH ASSOCIATED SMOKE IN THE CABIN. MAINTNENANCE TROUBLESHOT SYSTEM AND FOUND THE ACM TO BE AT FAULT. UNIT WAS REMOVED AND REPLACED. SYSTEM OPERATIONAL CHECKED. ALL CHECKS GOOD.