The problem could be a bad door lock assembly if the control board does not see it's closed. You have to check it for continuity. Post the results as well as a picture of the old door lock. It will help to determine what you have to order in case the old door lock is bad.
Here are the breakdown diagrams and
Parts for Frigidaire LTF2140ES3 Washer - AppliancePartsPros.com
Gene.