As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE PERFORMING OPERATIONAL CHECK OF THE CAPTS O2 MASK MICROPHONE THROUGH PACES ON EMERGENCY MODE, IT WAS FOUND THAT PA EMERGENCY MODE WAS INOP. EMERGENCY POWER SUPPLY NR 2 WAS FOUND TO BE FAULTY. THE POWER SUPPLY WAS REPLACED AND OPERATIONAL CHECK IS GOOD.