As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FIRST OFFICER'S HSI OSCILLATES MORE THAN 60 DEGREES WITH HDG FLAG ANNUNCIATED. RMI ON CAPTAIN'S SIDE SIMULTANEOUSLY FLAGGED. RETURNED TO LAX. SWAPPED AHC 85 SIDE TO SIDE FOR TROUBLESHOOTING AND PROBLEM FOLLOWED. SWAPPED BACK AND REPLACED NR 2 AHC 85. REORIENTED AND OPS CHECKS GOOD.