Ran into the same problem with Nayax. Some techs are better than others at helping you through the problem. When I run into this situation with nayax readers I simply unplug the machine for 10 seconds then re plug it. Somehow it gets the reader to communicate with the machine. In the case of your Crane 167, Chard is correct. You gotta enable the MDB card reader setting. I ran into the same situation also. Good luck!