What was found
WHEN STARTING RT ENGINE, AFTER STARTER CUT OUT, NG AND ITT KEPT ACCELERATING. WHEN NG REACHES 85 PERCENT WHITE SMOKE APPREARS FROM VENTILATION SYSTEM. SMOKE IS FAIRLY DENSE WITH NO ODOR. MAINTENANCE BORESCOPED POWER UNIT, FOUND NO EVIDENCE OF OVERTEMP OR OTHER DEFECTS. REMOVED AND REPLACED DECU IAW GE MM 71-00-00. REMOVED AND REPLACED HMU IAW GE MM 73-00-00, OPS AND LEAK CHECKS GOOD.