What was found
UNIT PULLED FROM AIRCRAFT FOR RE-CERTIFICATION. BENCH TEST REVEALED ALTITUDE READ OUT WAS CONSISTENLY LOW PF ABOUT 20 FEET TO 150 FEET IN THE RANGE OF -1000 FEET 4,000 FEET. A CHECK ABOVE 4,000 FEET WAS NOT COMPLETED DUE TO THE LARGE ERROR AT THE LOW END. ENCODER OPERATION WAS ERRATIC, INACCURATE, AND UNRELIABLE. FROM ABOUT 1 TO 3 ON THE POINTER ROTATION, THE ENCODER WOULD FAIL COMPLETELY. THE GREY CODES WOULD GO BACKWARD FROM 7 TO ZERO AND FORWARD FROM 5 - 7. THE CODE WOULD STAY ON ONE CODE FROM ZERO TO 5, WITH EXCEPTION OF WHERE GREY CODE VANISHED AT 1 - 3. SUBMITTER STATED AT NO POINT WAS ENCODER OUTPUT CORRECT. (X)