I just purchased a SD 90 Norfolk Southern Engine the other day.  The train runs great but the true blast II sound does not seem to be working at all.  I am using a CW-80 transformer that came with a Lionel Polar Express set.  The bell and horn buttons on the transformer operate lionel trains and cars just fine.  Is there something that I can do to further diagnose this or do I need to just send it back to the place that I purchased it?