DIAGNOSIS The motor is experiencing excessive load or friction. For the SS151, this is commonly due to an overloaded pitcher or a blade assembly/drive socket binding issue specific to the high-speed setting.
FIX 1. Immediately turn off the unit. 2. Check the total volume in the pitcher. Do not exceed the 40oz max liquid fill line for the single-serve function. 3. For the full pitcher, do not exceed the 'MAX' line. 4. Ensure ingredients, especially frozen fruit, are cut to a size appropriate for the feed chute. 5. Disassemble and re-lock the blade assembly, ensuring it rotates freely by hand when unlocked.
IF THAT DIDN'T WORK The grinding may be internal. The plastic drive gears connecting the motor to the socket can strip under high load. This is a base unit failure. Listen closely: if the noise is a high-pitched mechanical grind from the base, not the pitcher, the gears are likely damaged.
HEADS UP The 'SMOOTHIE' setting uses a programmed high-torque, variable-speed cycle. It places the most stress on the system. Always use the 'PULSE' function to initially break up large frozen chunks before running a continuous cycle.