As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SELECTED ENGINE ANTI ICE ON, DESCENDING THROUGH 30,000 LT ENGINE COWL ANT-ICE LIGHT REMAINED BRIGHT. CYCLED SWITCH SEVERAL TIMES AND IT DIMMED AT 6000, NOTICED LIGHT AGAIN IN BRIGHT IN TRANSIT POSITION CYCLING SWITCH DID NOT WORK, STAYED BRIGHT UNTIL ANTI ICE DESELECTED. ACFT GROUNDED. REMOVED NR 1 ENGINE COWL ANTI ICE VALVE IAW AMM 30-21-11-000-801. REPLACED NR 1 ENGINE COWL ANTI ICE VALVE IAW AMM 30-21-11-400-801. OPS AND LEAK CHECKED GOOD.