Physical damage, magnetic strip deactivation, dirt/grease/grime on the card reader, or water damage can cause this.
Try processing a different, NON EBT card. This will help determine if the customer’s card is the issue.
If you get a “Denied 56” message, then the machine is functioning properly and the card itself or the customer’s account may be the problem.
If you do not get any response or a Denied 56 error, then restart the terminal.
If you’re still having trouble, please submit a support request.