As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CARGO FIRE SYSTEM TEST DID NOT INITIATE WHEN FIRST IRS ALIGN SWITCH WAS ROTATED O NAV. POSSIBILITY SOMEONE HAD ROTATED IRS ALIGN SWITCH TO NAV THEN OFF BEFORE THIS CREW ARRIVED ACFT, IF SO OPS IS NORMAL. SYSTEM OPS CHECKS NORMAL 26-15-01-5MM.