What was found
(CAN) DURING T/O ROLL, THE ACFT AUTOMATIC TAKEOFF POWER CONFIGURATION SYSTEM, ATPCS, AIRFRAME, WOULD NOT ARM. THE T/O WAS ABORTED AND THE ACFT RETURNED TO THE RAMP. EXTENSIVE TROUBLESHOOTING RESULTED IN THE REPLACEMENT OF BOTH ENGINE`S AUTO FEATHER UNIT, AFU, BEFORE THE ACFT WAS RETURNED TO SERVICE. INVESTIGATION IS ON-GOING AS TO WHY BOTH AFU`S WOULD HAVE APPEARED TO HAVE HAD PROBLEMS AT THE SAME TIME.