As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
READS 300 FEET LOW AT 800 FEET. FOUND UNIT TO HAVE NO ANALOG ALTITUDE OUTPUT VOLTAGE. REPLACED INTEGRATED CIRCUITS I501, I529 AND CAPACITOR C513. REPAIRED PROBLEM. ALIGNED AND CALIBRATED UNIT. INSTALLED MOD VOLTAGE DECAL. BENCH CHECK GOOD.