What is the most common reason why an ice maker isn't working?

The single most frequent reason an automatic residential refrigerator ice maker stops producing ice is a frozen or obstructed water fill tube. When residual water droplets freeze over the tip of the fill tube, a solid ice plug forms, blocking incoming water from reaching the mold tray during subsequent cycles. Other common reasons include a closed household water supply shutoff valve, a kinked copper or plastic supply line behind the fridge, a defective water inlet valve, or an ice storage bin that has jammed the mechanical bail arm in the "off" position. You can troubleshoot by inspecting the fill tube and bail arm position. You can verify that your corrective action is successful when clearing ice blockages or opening water valves restores normal water filling and ice harvesting.