As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IAH - FLIGHT 2890, DURING PRE-FLIGHT INSPECTION, THE NUMBER ONE ELECTRIC HYDRAULIC PUMP FAILED AND A SMOKE SMELL WAS REPORTED IN THE COCKPIT. MAINTENANCE OPERATIONALLY TESTED THE ELECTRIC HYDRAULIC PUMP WITH NO DEFECTS NOTED, AND COULD NOT DUPLICATE THE SMOKE SMELL. THE AIRCRAFT WAS THEN APPROVED FOR RETURN TO SERVICE.