As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LAX INFLIGHT T283/31, AT CRUISE ALTITUDE TURNED ON CENTER PUMPS. BOTH PUMPS FAILED TO OPERATE. RETURNED TO LAX. LANDED WITHOUT INCIDENT. REPLACED LEFT AUXILLARY TANK OVERRIDE BOOST PUMP PER MM 28-22-05. ACCOMPLISHED OVERWEIGHT LANDING INSPECTION. SYSTEM GROUND CHECKED NORMAL OPERATION.