What was found
EICAS MSG ENG CORE ANTI .ICE L AT APPROX. 8000 FT. BOOSTER ANTI-ICE VALVE (LT ENG) FAILED CLOSED REF FIM DMC-B787-A-G75-00-F0-23A-421A-A. REFER TO LOG 7082521 FOR BOOSTER ANTI ICE ON LT ENG REF DMC-B787-A-G75-11-02 & PRESS SENSOR REF AMM G75-11-02. ACCOMP TEST 18, OPS TEST REF DMC-787-A-G71-00-00-23B-320A-A. TEST PASSED. ENG BOOSTER ANTI-ICE VALVE FAILED CLOSED. LOSS OF ANTI-ICING AT ENGE CORE INLET. AHM BOOSTER ANTI-ICE VALVE (LT ENG) FAILED CLOSED REF FIM DMC-B787-A-G75-00-F0-23A-421A-A. REPLACED #1 ENG BAI PRESS SENSOR REF AMM G75-11-02. OPS TEST GOOD. R & R LT ENG BOOSTER ANTI ICE VALVE REF DMC-787-A-G75-11-02 AND PERFORMED TEST 18 DMC-787-A-G71-00-00-23B-320A-A. TEST PASSED.