As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MODERATE TO STRONG BURNING ODOR WAS NOTICED IN COCKPIT AFTER DEPARTURE, ODOR BECAME FAINT AND THEN STRONGER SEVERAL TIMES. REMOVED AND REPLACED NR 4 PDU COOLING FAN ASSY. WITH A NEW FAN ASSEMBLY. OPS CHECK GOOD NO ODOR NOTED IN CABIN. WORK PERFORMED IAW FALCON 2000 MM 34-001.