What was found
RETURNED TO DEPARTURE, ENROUTE THE FOLLOWING ECAM APPEARED, AIR PACK 2 REGULATOR FAULT. CABIN COCKPIT TEMPERATURE CLIMBED TO 85 DEGREES F, MANIFOLD TEMPERATURE AT 85, 85, 84. CHECKED PFR, IT SHOWED NR 2 BYPASS VALVE FAILED. VERIFIED NR 2 BYPASS VALVED SEIZED IN THE CLOSED POSITION. R & R NR 2 BYPASS VALVE IAW AMM 21-61-53-000-001-A. LEAK CHECKED OK. NR 2 PACK, OPS CHECKED NORMAL.