If the reader is displaying two lines (- -) after being in the sensor for 15 seconds, back it out of the Smart Sensor. Check to see if this problem occurs with multiple sensors (not just related to an individual sensor). If the problem occurs with another Smart Sensor, then most likely the problem is that the connector at the bottom of the Easy Reader is not making proper contact with the sensor(s). Inspect the connector to see if any of the leaf springs are damaged, bent, twisted, etc. If that does not result in a solution, make sure you have tried a new set of batteries. If the problem still exists, the proper recourse is to send it in for repair and/or replacement.