As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED AN AVNX MAU3 FAIL IN FLIGHT, DECLARED AN EMERGENCY AND LANDED AT PNS WITHOUT INCIDENT. MAINTENANCE WAS DISPATCHED TO THE AIRCRAFT TO TROUBLESHOOT. MAINTENANCE REMOVED AND REPLACED THE POWER SUPPLY 1 IN MAU 3, PER EMB AMM AND PERFORMED OPS CHECKS. A/C WAS THEN RETURNED TO SERVICE.