What was found
CREW DIDN'T GET A GEAR NOT DOWN WARNING WHEN THROTTLES WERE RETARDED, WHEN THE LANDING GEAR WAS SELECTED DOWN, THERE WAS NO RED INTRANSIT LIGHT AND THE GEAR DOWN 3 GREEN INDICATORS DIDN'T COME ON. CREW PERFORMED A FLYBY OF THE TOWER, WHICH VERIFIED ALL 3 GEAR WERE EXTENDED. CREW PERFORMED MANUAL EXTENSION PROCEDURES TO VERIFY GEAR WAS LOCKED DOWN. CREW LANDED WITH NO FURTHER PROBLEMS. MAINTENANCE FOUND LANDING GEAR TIME DELAY PRINTED CIRCUIT BOARD HAD FAILED. PART WAS REPLACED AND LANDING GEAR AND SYSTEMS OPS CHECKED GOOD.