As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 823 JFK-SDQ, AIR TURNBACK TO JFK - CREW DECLARED EMERGENCY DUE TO NR 2 BLEED FAULT FOLLOWED BY NR 1 BLEED FAULT AFTER CROSSBLEED OPENED. REMOVED AND REPLACED ENGINE NR 2 FAN AIR VALVE CONTROL THERMOSTAT REF AMM 36-11-43. OPS CHECK OK.