Hello @sk141 thanks for your post. When you say the card reader doesn't work, what part are you specifically referencing...the magnetic stripe reader, the slot to "dip" the chip, or the tap for payment? Are all of those not working?
Is this register the version with the customer-facing screen? If so, you could try "ejecting" the customer facing screen and re-inserting...or if you use the extended cable, you could try disconnecting that cable and resetting the display directly into the front of the register, and see if that fixes the reader.
