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 SHOWS ALL RED RETURN BEYOND 80 NM RING. WORKS NORMALLY IN MANUAL MODE. ACFT GROUNDED. R & R WEATHER RADAR TRANSCEIVER REF MM 34-43-41-400-801 & 34-43-41-000-801. OPS NORMAL, REF MM 34-43-00-710-802-001. ETOPS GROUND VERIFICATION TEST PASSED. REPEAT DISCREPANCY THE FOLLOWING DAY, REPLACED WEATHER RADAR CONTROL PANEL REF 34-43-91. OPS NORMAL IAW SAME.