As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE AT FL370 WITH NO VISIBLE WEATHER, WX RADAR SHOWING TWO NARROW BANDS OF WEATHER FROM CTR OF DISPLAY TO EDGE OF DISPLAY AT ALL RANGES. SAME PATTERN IN AUTO & MANUAL. WITH CONVECTIVE ACTIVITY AHEAD OF AIRPLANE LATER IN FLIGHT, NO RETURN DISPLAYED. AFTER APPROXIMATELY ONE HOUR, APPEARS TO BE FUNCTIONING NORMALLY. ACFT GROUNDED. WX RADAR TESTED GOOD IAW FIM 34-43, TASK 801.