As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
C- HYDRAULIC PRESSURE EICAS MESSAGE AND BOTH CENTER HYDRAULIC LOW PRESSURE LIGHTS ILLUMINATED, AFTER ACCOMPLISHMENT OF QRH NO HELP, CREW DECIDED TO RETURN BACK TO SNN. UNEVENTFUL LANDING WAS ACCOMPLISHED. TROUBLESHOOT SYSTEM AND FOUND CENTER HYDRAULIC AIR PUMP AUTO FUNCTION INOPERATIVE. ITEM DEFERRED PER MEL 29-11-4-1. CENTER HYDRAULIC SYSTEM TRANSMITTER REPLACED OPERATES NORMALLY.