As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT WING ANTI ICE VALVE WOULD NOT OPEN WHEN TURNED ON LEFT VALVE CAUTION LIGHT ANT ANTI ICE VALVE MASTER CAUTION ILLUMINATED WHEN POSITION ON. GROUNDED - YES. REMOVED & REPLACED LH WING ANTI-ICE VALVE REF B737-9 AMM 30-11-11/401. OPS CHECK PASS.