As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAXI AFTER APU TURNED ON WITH APU BLEED PUSHED IN, "RECIRC SMK DET FAIL" EICAS MESSAGE SHOWED. RAN CHECKLIST, WITH NO MESSAGE CHANGE. RECIRCULATION SYSTEM SMOKE DETECTOR PACKS OPERATIVE. REMOVED FROM SERVICE. REMOVED AND REPLACED RECIRCULATION BAY SMOKE-DETECTOR, PER E175 AMM 26-16-01-000-801-A AND 26-16-01-400-801-A. OPERATIONS TEST, PER TASK 26-16-01-710-801-A CHECKS GOOD. NO FAULTS OR DEFECTS NOTED. THIS CLEARS DEFECT 941321. PLACARDS REMOVED. MTX PROCEDURES REVERSED. AIRCRAFT RETURNED TO SERVICE.