Snapper 285Z 27hp/ Cut Height Adjusment

I need help. The electric cut height adjusment system is not working. Adjusment button makes the humming sound when pressed and we can see the bolt turning in either direction, but the deck does not move. Owners Maunuel does not have any information or diagrams of how hookup should be. Is there any kind of diagram out in this forum. Does anyone know if there is any kind of saftety lock that might be engaged, where it might be and how to reset it.
Thank you
Redlawnlizardlady