As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIR-DUCT OVERHEAT IN COCKPIT ANNUNCIATOR ACTIVATED, WHITE SMOKE FILLED COCKPIT ON GROUND. RAN A/C APU FOR 45 MINUTES FOUND THE TEMP CONTROL TO BE STUCK IN THE FULL HOT POSITION IN AUTO MODE. NO SMOKE IN THE A/C DURING OPS CHECK. AUTO TEMP CONTROL HAS BEEN PLACED ON MEL. REF NETJETS W/O 560-5365-288OR MEL, SYSTEM OPERATES WITHOUT DEFECTS.