Icemaker mold heater, not turning on. Replaced with a brand new

It indeed seems like there might be an issue with what activates the mold heater in your situation. Allow me to provide further insights.

In most refrigerator models, including Samsung, the ice mold heater is controlled by the icemaker module or a related control board. This control board receives signals from various sensors and components to determine when to activate the mold heater. These signals can include temperature readings, ice level detection, and the position of various mechanical components.

Since you mentioned that the water flows correctly and the gears turn, it suggests that the mechanical components related to ice production are functioning properly. This leads us to investigate the electrical side of things: the control board and associated sensors.

Here are a couple of suggestions for further troubleshooting:

1. Check the control board: Locate the control board responsible for managing the icemaker functions. Inspect it for any visible signs of damage or burning. Sometimes, components on the board can fail, causing issues with power distribution.

2. Test the sensors: There may be temperature sensors or other sensors in the icemaker assembly that provide input to the control board. Check if these sensors are functioning correctly by testing their resistance or voltage output (consult the refrigerator's manual or seek professional support for specific instructions on testing procedures).

3. Consider professional assistance: If you've already replaced the icemaker unit and have gone through these troubleshooting steps without success, it may be worthwhile to seek assistance from a professional technician who specializes in appliance repair. They can diagnose the issue more precisely and help resolve it.

I hope these suggestions prove useful in identifying and resolving the issue with your ice maker.