As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING MAINTENANCE INSPECTION THE CARGO SMOKE DETECTORS WOULD NOT TEST. THE AIRCRAFT WAS REMOVED FROM SERVICE. REMOVED AND REPLACED THE AFT CARGO SMOKE DETECTOR IAW EMB AMM 26-15-01. THE OPERATIONAL CHECK WAS GOOD. THE AIRCRAFT WAS RETURNED TO SERVICE.