As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: AN EMERGENCY WAS DECLARED DUE TO: WEATHER RADAR FAILED ENROUTE. ATTEMPTED TO TEST. WHEN PERFORMING THE TEST, THERE WAS A GRINDING NOISE FROM BELOW OUR FEET; AIRCRAFT DIVERTED TO AND LANDED SAFELY AT ORD. REMOVED AND REPLACES WEATHER RADAR ANTENNA DRIVE UNIT. PER AMM 34-43-11.