As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ORD INFLIGHT - CREW REPORTED PRIMARY PRESSURIZATION CONTROLLER FAILED TO KEEP CABIN ALTITUDE. SWITCHED TO STANDBY CONTROLLER AND TRANSFER LOCKOUT AND STANDBY ON BLUE LIGHTS CAME ON. CABIN ALTITUDE WENT TO NORMAL. CREW REQUESTED RAPID DESCENT FROM FL350 TO FL140. LANDED ORD WITHOUT INCIDENT. FOUND PRIMARY/STANDBY SWITCH ON OVERHEAD BAD. ACTIVE LIGHT FLASHING BETWEEN CONTROLLERS. REPLACED OVERHEAD PRESSURE PANEL. SYSTEM GROUND CHECKED NORMAL OPERATION.