What was found
PASSING 20,000 FEET ON DEPARTURE, SMOKE IN THE COCKPIT. DECLARED EMERGENCY. COMPLIED WITH QRH. RTB. ONCE WE DEPRESSURIZED THE COCKPIT, SMOKE WENT AWAY. FIRE DET 1 FAULT ALERT UNDER MAINTENANCE MENU. ***EMERGENCY DECLARED*** PERFORMED PACK BURN OUT PER AMM 21-53-00-7 AND REPLACED COALESCE BAGS FOR ALL 3 PACKS, REFERENCE WRI 21-50/2149.