As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CLE - FLT 3295 - CREW REPORTED, THAT THE AIRCRAFT WOULD NOT HOLD PRESSURIZATION IN AUTO OR MANUAL MODES. AIRCRAFT RETURN TO FIELD. MAINTENANCE INSPECTED THE AIRCRAFT THEN REMOVED AND REPLACED THE ELECTRO-PNEUMATIC OUTFLOW VALVE IAW EMB-120 MM 21-30-03. OPERATIONAL CHECKS WERE SATISFACTORY. AIRCRAFT RELEASED FOR SERVICE. (M)