As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PHL - FL 1268 - CAPTAIN REPORTED, THAT THE LEFT ENGINE BLEED AIR VALVE WOULD NOT OPEN AT TAKEOFF POWER. RECYCLED SWITCH AND CIRCUIT BREAKER WITH NO HELP. FLIGHT RETURNED TO FIELD AT PHL AND LANDED WITH NO FURTHER INCIDENT. MAINTENANCE REMOVED AND REPLACED THE FOLLOWING LISTED ITEMS PER THE MM. LEAK CHECK AND OPS CHECK GOOD. REFERENCE USAASB96166.