What was found
PRIOR TO STARTING AN ILS APPROACH, STBY PWR LIGHT ILLUMINATED. NOTED 3 OF BUSS 1 C/B'S HAD POPPED, ALL SYSTEMS FUCTIONED NORMAL. TURNED LIGHTS OFF & ANTI-ICE SYSTEM LEFT ON DUE TO ICING CONDITIONS. TURNED ON TAXI & LANDING LIGHTS BEFORE LANDING & SEVERAL ANNUNCIATOR LIGHTS INCLUDING ENGINE FIRE WARNING ILLUMINATED. AFTER LANDING, PILOT PULLED FUEL SHUT-OFF CLOSED & SECURED ENGINE, DECLARED AN EMERGENCY. NO APPARENT FIRE DAMAGE NOTED. MX FOUND NO WIRING ISSUES IN C/B PANEL. GROUND RUN CHECKED GOOD. PERFORMED 2ND GROUND RUN, DISCREPANCY WITH ALT OFF. STBY POWER LIGHT DID NOT COME ON DURING LOAD TEST, NO C/B'S POPPED. FOUND ALT CONTROLLER DEFECTIVE. R & R ALT CONTROLLER.