Simply test thermostat by placing ice on stat unit should turn off in less than 20 seconds. Remove ice machine should come on in a minute or two. If not reacting properly there is an adjustment in rear of machine. Follow cap tube back to thermostat. Warmer more sensitive. Colder less sensitive.

I don't have the details on you machine but if I were going to trouble shoot this problem, assuming its a temperature probe I would power off the machine, remove the access panel and remove the temperature probe and check it with an Ohm meter or continuity checker for proper functioning by putting the probe in ice and see if it opens electrically. Sometimes the probe is not a simple thermostat type. The bin control on some machines is optical. The ice pile breaks a light beam to turn off ice making. Sometimes the probe is a thermistor. These latter two kinds of probes have electronics connected to them. A simple ohm check will not work for these cases. You can tell what kind you have by looking at it carefully. The thermostat kind that can be checked with a continuity checker or ohm meter is a sealed metal tube. The optical type has a light source and a separate pick up sensor. The thermistor type is a very small device on the end of a pair of wires. For the optical type or the thermistor type write back for more details.