As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 276, SJU-BDL(AIR TURN BACK TO SJU). CAB PR EXCESS CAB ALT WARNING DISPLAYED CLIMBING THROUGH FL310 PACK 1 APPARENTLY WEAK.; C/W R/R VALVE-FLOW CONTROL ASSY. PACK #1 AND SECURED AS PER A.M.M. 21-51-51-PB 401 PERFORMED BITE TEST A/C SYSTEM PASSED NO FAULT ON MCDU ALSO PERFORMED TEST CABIN PRESS CONTROL PASSED AS PER A.M.M. 21-31-00-710-005.