As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SHIP 3895 - PRESS / DE - DUE TO CABIN ALTITUDE WARNING. FLIGHT DESCENDED TO 18,000 FEET AND CONTINUED. CORRECTIVE ACTION: PERFORMED DCPC 1-2 BITE CHECKS. NO TROUBLE FOUND. REPLACED BOTH CABIN PRESSURE ALTITUDE SWITCHES S128 AND S1153. PERFORMED SINGLE PACK CONFIDENCE CHECKS LEFT AND RIGHT PACKS. OPS CHECKS GOOD.