As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RETURNED TO GRR DUE TO PRESSURIZATION ISSUES AND NUMEROUS FAULTS DISPLAYED IN COCKPIT AFTER DEPARTURE. PAX O2 MASKS DEPLOYED AUTOMATICALLY. CORRECTIVE ACTION: REMOVED & REPLACED NUMBER 1 IASC OPS CHECK GOOD. (LP# 8706293; AIRCRAFT WAS GROUNDED)