As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LAX FLIGHT NR 2304: ON DESCENT, NR 1 BLEED HOT CAUTION ILLUMINATED. AS PER E/A CHECKLIST, TURNED NR 1 BLEED OFF. LIGHT REMAINED ILLUMINATED FOR REMAINDER OF FLIGHT. MAINTENANCE C/W Q400 FIM TASK 36-10-00-810-809. REMOVED AND REPLACED L DUCT LEAK SWITCH IAW Q400 AMM TASK 36-11-21-000-801 AND 36-11-21-400-801. OPS TEST OF THE BLEED AIR SYSTEM CHECKED GOOD. INTERROGATED CDS WITH NO FAULTS NOTED. AIRCRAFT RETURNED TO SERVICE.