What was found
NR 1MCDU SCREEN GOES BLANK FOLLOWED BY ELECTRICAL SMOKE EMINATING WITHIN THE COCKPIT. AFTER POWER UP WITH AVIONICS ON, FLIGHT PLAN PROGRAMMED AND READY TO GO. NR 1 MCDU SCREEN SUDDENLY GOES BLANK. THE ODOR OF ELECTRICAL SMOKE BEGINS AND THE EICAS MOMENTARILY DISPLAYS AN AMBER ASCB BUSS FAIL LIGHT FOLLOWED BY A AMBER MONITOR WARNING FAIL LT LIGHT 30 TO 45 SECONDS LATER THE 2 AMBER LIGHTS DISAPPEAR FROM THE EICAS DISPLAY. CONFIRMED 1 MCDU WAS THE CAUSE OF THE EICAS MSG AND SMOKE. INSPECTED 1 MCDU CONNECTORS/PINS AND FOUND THEM IN GOOD CONDITION. R & R 1 MCDU IAW MM 23-80-00. PERFORMED EPIC OPS TEST IAW MM 34-23-10. OPS CHECKED GOOD.