As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SEA FLIGHT NR 2419: IRS ALIGN FAULT AFTER ATTEMPTING ALIGNMENT. RECEIVED CPU PMC MESSAGE. AIRCRAFT RETURNED TO BLOCK. MAINTENANCE PERFORMED IRS OPS TEST. CHECKS GOOD IAW Q400 TAC 6343508. NO PARTS REPLACED. AIRCRAFT RETURNED TO SERVICE.