As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ETOPS SIGNIFICANT SYS - F/O HSI INTERMITTENT. SELECTING ALT EFI DOESN'T CORRECT THE FAULT. T/S IAW FIM 34-22-00/101, FIG 106. REMOVED INDICATOR AND CLEANED LINT FROM AIR INLET SCREEN. REINSTALLED INDICATOR. HSI CKS OK IN ALT EFI AND NORMAL. F/O HSI OK FOR SERVICE.