What was found
DURING AUTO FEATHER TEST, THE A/F TEST ABORT AND A/F TEST FAILED MESSAGES APPEARED ON THE ED.REMOVED FROM SERVICE. EMU SHOWING THE FOLLOWING FAULTS: #1 PROP: 70B, #2 PROP: 70B AND 398B. COMPLIED WITH DHC-8-400 FIM TASK#'S 61-20-02-810-835 AND 61-20-08-810-818. FAULTS CLEARED AND AUTOFEATHER AND UPTRIM SYSTEM OPERATIONAL TEST GOOD. REFERENCE PRODUCTION WORK ORDER 312889 TASK CARD N/R-00002 FOR ADDITIONAL TROUBLE SHOOTING PERFORMED AND REPLACEMENT OF #1 PROPELLER ELECTRONIC CONTROL UNIT FOR PRECAUTIONARY MEASURES. AUTOFEATHER AND UPTRIM SYSTEM OPERATIONAL TEST GOOD SEVERAL TIMES WITH ENGINES RUNNING AND STOPPED IAW DHC-8-400 MM TASK# 61-20-00-710-810. ALL INDICATIONS NORMAL DURING TESTS AND NO ENGINE/PROPELLER FAULTS FOUND IN CDS AFTER TESTS.RETURNED TO SERVICE.