As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT#478, LAS-BOS. (ETOPS) 'AUTOMATIC CONTROL CROSSBLEED VALVE INOP ( CROSS BLEED VALVE ); APU X-FEED FAULT CAME ON WHILE APU BLEED WAS RUNNING, NO ENGINES RUNNING. REMOVED AND REPLACED CROSSBLEED VALVE IAW AMM 36-12-52 AS PRECAUTIONARY. OPS CHECK OK. MDDR CLEARED. PLACARD REMOVED. MX-4 UPDATED.