As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WEATHER RADAR IN AUTO MODE WITH GAIN SET AT 12 O`CLOCK WILL NOT DISPLAY RETURNS. TESTED NORMAL, WORKS NORMAL IN MANUAL MODE. WORK IN AUTO MAP MODE. ACFT GROUNDED. PERFORMED WEATHER RADAR OPS TEST, REF 34-43-91. SYS CHECKED NORMAL. NO FAULTS FOUND. NO HISTORY IN 90 DAYS.