As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRBORNE WX RADAR INOP. WHILE FLYING THROUGH RAIN WITH 3-5 MILES VISIBILITY HAD RADAR ATTENUATION OFF THE NOSE WITH SOLID RED AND PURPLE UP TO 20 MILES OFF THE NOSE. SCANNED FROM 0 UP TO +10 WITH THE SAME RESULTS. KNOCKED THE GAIN DOWN THREE CLICKS BEFORE WE DIDN'T HAVE SOLID RED OR PURPLE ON ENTIRE RADAR SCAN. RETURNED TO MEM. REPLACED WEATHER RADAR. OPS CHECK GOOD.