As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT 36000 CABIN ALTITUDE BEGAN TO CLIMB AFTER CONTROLLER WAS WORKING FOR ONE + HOURS. RATE OF CLIMB SUCH THAT HABITUAL LEVELS COULD NOT BE MAINTAINED W/O DESCENT TO LOWER ALT, AUTO SYSTEM WORKED GOOD AND SCHEDULED DIFFERENTIALS AND ALTS MAINTAINED AS DESIGNED. REMOVED AND REPLACED DIGITAL CONTROLLER AS PER EMB AMM 21-31-01. OPS GOOD. AIRCRAFT RETURNED TO SERVICE.