As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE NOSE GEAR DID NOT EXTEND ON FIRST ATTEMPT ON APPROACH INTO IAH. A MANUAL EXTENSION WAS PERFORMED AND THE NOSE GEAR SHOWED DOWN AND LOCKED. THE AIRCRAFT LANDED WITHOUT INCIDENT. THE LANDING GEAR SELECTOR VALVE WAS REMOVED AND REPLACED IAW MM 32-31-51. LEAK AND OPERATIONAL CHECKS WERE GOOD.