As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ACFT HAD SLIGHT ODOR, HAZE IN CABIN AND COCKPIT. FLIGHT CREW NOTED 1 PHASE OF CARGO HEAT C/B POPPED. PULLED REMAINING C/BS AND ALL DISSIPATED. MAINTENANCE FOUND THE FORWARD CARGO HEAT INTERNAL ELEMENT FAILED AND REPLACED THE FORWARD CARGO HEATER. MAINTENANCE ALSO COMPLIED WITH THE PNEUMATIC TROUBLESHOOTING TASK CARD WITH NO OTHER DEFECTS NOTED. THE ACFT HAS RETURNED TO SERVICE.