What was found
CLIMBING THROUGHT 8000 FT, AFTER TAKE OFF, RECEIVED A LAVATORY SMOKE EICAS WARNING. F/A DID NOT SEE SMOKE BUT SMELLED UNUSUAL FUMES. RETURNED TO DEPARTURE. SMELLED FUMES IN COCKPIT ON FINAL. REMOVED AND REPLACED THE LT LAVATORY BALLAST IAW AMM 33-28-02. OPS CHECKED GOOD.