As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
#1 ENGINE COWL VALVE FAILED IN CLOSED POSITION. BLUE LIGHT STAYS ON IN ON POSITION OF SWITCH. GROUNDED - YES. FLT CREW REPORTS #1 ENG COWL VALVE STARTED WORKING ON SEVERAL CYCLES OF VALVE, DID NOT FAIL. PERFORMED B737-800 FIM 30-21 TASK 805. OPS CK GOOD.