What was found
(CAN) ON APPROACH THE NR 1 INVERTER WARNING LIGHT ILLUMINATED AND THE NR 1 DUAL FEED BUSS CB TRIPPED. AS GEAR WAS BEING EXTENDED AT THE TIME, GEAR DOWN SHOWED 3 GREEN BUT GEAR INTRANSIT LIGHT ALSO ILLUMINATED. PILOT OVERSHOT RUNWAY AND PERFORMED EMERGENCY GEAR EXTENSION PROCEDURE, THIS CONFIRMED GEAR DOWN AND LOCKED. TROUBLESHOT SYSTEM AFTER LANDING AND FOUND A FAULTY DIODE, THIS DISABLED A BUSS FEEDER TO NR 1 BUSS WITH THE AIRCRAFT IN THE APPROACH AT NIGHT, THERE WAS MORE THAN A 50 AMP DRAW FROM THE NR 1 BUSS SO THE REMAINING CB TRIPPED. THIS ALSO HAD THE EFFECT OF SHOWING A WARNING FOR GEAR INTRANSIT AND TOOK ALL THE NR 1 BUSS FEED SYSTEMS OFF LINE.