DIAGNOSIS A foreign object or ice fragment is jammed in the auger mechanism. The auger is the spiral blade that pushes ice up the chute.
FIX Unplug the machine immediately. Remove all ice from the basket. Look up into the ice discharge chute. Use a flashlight. You may see a chunk of ice or debris. Use long plastic tweezers or a chopstick to carefully dislodge it. Do not use metal. Plug back in and run a cleaning cycle.
IF THAT DIDN'T WORK The noise is internal. The auger motor bearings or the gear drive connecting the motor to the auger shaft have failed. This requires disassembly. You must remove the top cover and interior panels to access the motor and gearbox.
HEADS UP That grinding noise is metal on plastic. Continuing to run it will shred the gear drive. If you hear it, stop the machine within 10 seconds to prevent catastrophic damage.