What was found
SMOKE IN COCKPIT, ENTERED IN STEADY HEAVY STREAM IN AREA OF BRACE IN C/B PANEL BY CAPT LEFT SHOULDER. LAVATORY MIRROR C/B FOUND TRIPPED. CHECKED P-18 PNL FOR BURN WIRE AND CIRCUIT BREAKER, ALL CHECK NORMAL. FOUND FWD LAV MIRROR LT BALLAST BAD. PULLED AND COLLARED LAV MIRROR LT C/B. CONTINUED PER MEL 33-2. DURING OVERNIGHT CHECK, REMOVED AND REPLACED LIGHT BALLAST PER BOEING MM.