If it prints, you obviously have a printer cable and not a communication cable. It is important to note that the communication cable could be functioning correctly and the computer will still not recognize the interface. This is one of the reasons it is so difficult to component check a single interface lab. Also, it is important that you check the SensorNet software and make sure you are connected to the proper comm port. With the communication cable checked and determined to be operating properly, we are left with the interface itself.
Many factors can come into play with the proper functioning of the interface.
All of these factors can change the performance of the interface. Then it is assumable that the problem is within the interface and it must be sent in for further servicing. If indeed you need to send your unit in for servicing, please send the unit in with the communication cable and power supply. It is not necessary for you to include any of your sensors or probes unless you think they may also be malfunctioning. If it is imperative that you have an interface to perform your lessons and cannot wait for the service period, call us and we will send you a loaner interface to use until we can get your system serviced and back to you.