What was found
WX RADAR DISPLAYED A PIE SHAPED RETURN FROM 0 TO 160 NM AND OTHER RANGE MAXIMUMS AS WELL, GREEN TO FULL RED AT THE 10 O'CLOCK POSITION. THIS DISPLAY REMAINED WITH HEADING CHANGES. IT REMAINED AFTER CYCLING POWER. IT WAS MORE PRONOUNCED IN AUTO BUT ALSO WAS DISPLAYED MORE LIGHTLY IN MANUAL. ACFT GROUNDED. PERFORMED WEATHER RADAR SYSTEM BITE PROCEDURE IAW FIM TASK 34-43, TASK 801. NO FAULTS NOTED. OPS CHECK NORMAL. NO HISTORY PAST 30 DAYS.