As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 590 PBI-HPN, CREW DECLARED AN EMERGENCY AND AIRCRAFT DIVERTED TO JFK. AT CRUISE ALT, 45 MINUTES IN TO FLIGHT AVNX MAU2A FAIL AND ASSOCIATED MSGS APPEARED ON EICAS. RAN QRH 45 MINUTES LATER IT DISAPPEARED. REMOVED AND REPLACED MAU2 NIC/PROC NR 1 CARD PER AMM 31-41-04.