As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NR 2 HF SHOWED FAILED MESSAGE IN FREQ WINDOWS. ACFT GROUNDED. PERFORMED HF COMM. SYS OPS TEST IAW MM 23-11-00 AND W/HF FREQ'S IN RTP 1&2 PANELS, NO FAILED MESSAGES SHOW. DUE TO HISTORY, R & R NR 2 HF TRANSCEIVER IAW MM 23-11-21. OPS NORMAL REF SAME MM AND HF SYS TEST REF 23-11-00, HF COMM. TEST WITH SAN. FRAN. GROUND VERIFICATION TEST GOOD.