As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ALT DISAGREE CAUTION, COMPLIED WITH QRH WITH MCC DIRECTION, DETERMINED CA ALTIMETER UNRELIABLE. ALTITUDE DIFFERENCE INCREASES AS PER PREVIOUS WITH TAS INCREASE IAW PREVIOUS WRITEUP. CA 34020, FO 34220 STANDBY 34520ON INITIAL CAUTION MESSAGE (MACH .80) CORRECTIVE ACTION: REPLACED LT ADC IAW AMM 34-12. PERFORMED LOW LEVEL LEAK CHK IAW AMM 34-11. CHECKED OK.