As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: MUSTY SMELL REPORTED BY FLIGHT ATTENDANT IN BACK AFTER TAKEOFF. MAINTENANCE FOUND THE POWER TRANSFER UNIT (PTU) LEAKING HYDRAULIC FLUID INTO THE APU INLET AND REPLACED IT PER AMM 29-23-41. A SATISFACTORY LEAK / OPERATIONAL CHECK WAS ACCOMPLISHED.