What was found
AFTER BENCH ADJUSTMENT OF EEC, EEC WAS INSTALLED IN ACFT. DURING START OF ENGINE, EEC TRIPPED TO MANUAL MODE AND UNABLE TO RESET. AFTER EXTENSIVE T/S, DETERMINED EEC WAS UNSERVICEABLE. A REVIEW OF TEAR DOWN/REPAIR REPORT REVEALED EEC REMOVED FROM SERVICE FOR THE SAME FAILURE. FAA FORM 8130-3 STATED INSP ONLY. EEC RETURNED TO ALLIED SIGNAL FOR WARRANTY CONSIDERATION. THIS WAS SECOND EEC THAT FAILED WHILE CORRECTING A SQUAWK DURING THE SAME MAINT VISIT BY CUSTOMER. THE FIRST FAILED EEC WAS REPORTED ON A SEPARATE M OR D REPORT.