On a KM cuber, check the frost line, freeze cycle time and ice fill on the evaporator to assure proper TXV operation. The normal freeze cycle time is found on the performance data chart in the KM service manual. You must know the exact inlet water temperature to read the chart correctly. The normal ice fill will be from top to bottom and at the end of the freeze cycle. The last two passes will have slightly smaller ice cubes if the refrigerant charge is correct and the TXV is feeding properly.
Some units utilize multiple TXV s.
In this case each circuit should be treated individually as a single pass circuit when troubleshooting. On a flaker, the TXV maintains a constant suction pressure and evaporator temperature because the evaporator load is constant. The frost line will be consistent and within the same range as the KM cuber. A quick check for a TXV that is suspected bad is to check the valve swing. To do this, check the suction pressure 5 minutes into freeze.