As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ACCOMPLISHING AFTER TAKE OFF CHECK LIST, NOTICE LEFT WING VALVE BRIGHT BLUE LIGHT ILLUMINATED RAN QRH. CONTINUED TO DESTINATION SNIGLE PACK OPERATION CABIN PRESSURE 7.7 PSI, CABIN ALT 7800 FEET, RT PACK 42 PSI. ACFT ALT 370 WING ANTI-ICE SWITCH OFF POSITION. GROUNDED - YES. REMOVED AND REPLACED LH WING ANTI-ICE SHUTOFF VALVE PER B737-800 AMM 30-11-11. TEST OK A/C OK FOR SVC.