As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: FLIGHT ATTENDANT DISPLAY PANEL SHOWS CHECK SLIDE PRESSURE 4L. NO ACCOMPANYING CIDS MESSAGE ON STATUS PAGE. MAINTENANCE REPLACED DEU-B (300RH8) AND ACCOMPLISHED A SATISFACTORY OPERATIONAL CHECK PER AMM 23-73-47-400-001A.