As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON CLIMB OUT OF FLIGHT, THE CREW REPORTED THE CAPTAIN`S ALTIMETER FROZE UP (STOPPED CLIMBING) WERE PERFORMEING AN AIR-TURN-BACK. UPON ARRIVAL BACK, THE ALTIMETER BEGAN TO WORK AGAIN. MX REPLACED THE ALTIMETER AND RETURNED THE AC TO SERVICE. (K)