If you believe the temperature reported on your thermometer is incorrect, there are a few things you might do. This could be because the probe was pressed too far into the food or not pushed far enough. It could be making touch with bone, which would skew the reading. Check to ensure that the probe and wire have not absorbed or taken on moisture internally. If the plug or socket was exposed to water, the same thing might have happened. The probe may have failed due to contact with water or flame. The probe may be pinched or damaged in some circumstances. Check all of them and refer to the user manual for your smoker thermometer model. You may be able to avoid buying a new thermometer, but you may have to accept that the unit is fried.