What was found
AFTER ENGINE START, DC BUSS CAUTION LIGHT ILLUMINATED. RESET BUSS OK. NR 2 GENERATOR WOULD NOT RESET. MX STARTED NR 1 AND 2 ENGINES, DESELECTED EXTERNAL POWER SWITCH. TURNED NR 2 GENERATOR OFF, CAUTION LIGHT ILLUMINATED. TURNED NR 2 GENERATOR ON, LIGHT WENT OUT. NO DEFECTS NOTED, ALL VOLTAGES NORMAL. OPS CHECKS GOOD. ACFT RETURNED TO SERVICE. NO PARTS REPLACED.