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 RETURN TO JFK DUE TO AIR ENG 2 BLEED FAULT AT CRUISE ALTITUDE FL 370. QRH WAS FOLLOWED AND WHILE PERFORMING PROCEDURE THE FLIGHT CREW RECEIVED A SECOND AIR ENGINE BLEED 1 FAULT. AIRCRAFT BEGIN LOSING PRESSURIZATION AND AN EMERGENCY DESCENT WAS INITIATED. PRECOOLER TEMP ON NR 1 AND NR 2 WAS 240 DEGREES. THE TECHNICIAN REMOVED AND REPLACED NR 2 ENGINE THERMOSTAT AS PER AMM 36-11-43. OPS CHECK OK.