As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE EN ROUTE FROM SDF TO LGA THE CREW RECEIVED A 115 VAC OFF BUS MESSAGE ON EICAS. THIS FAILURE DISABLED THE WIND SHEAR ALERTING SYSTEM AND BECAUSE OF WIND SHEAR IN THE LGA AREA, THE AIRCRAFT DIVERTED TO PHL AND LANDED WITHOUT INCIDENT. MAINTENANCE REPLACED THE STATIC INVERTER WITH NO FURTHER DEFECTS NOTED.