As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ETOPS SIGNIFICANT SYSTEM: CAL POSITION ON RADAR SHOWS RADAR RETURNS ON ECLECTICALLY ACTIVE THUNDERSTORMS AS LIGHT RAIN, MANUAL POSITIONS FUNCTION NORMALLY. FOUND WX RADAR RT FILTER DIRTY. CLEANED IAW B737-800 AMM 34-43-09 PG 701, OPS CHECKED GOOD IAW B737-800 AMM 34-43-00 PG 501. NO DEFECTS NOTED.