DIAGNOSIS: The unit's internal thermal fuse or breaker has blown, cutting all power. This usually happens from overloading or a voltage spike.
FIX: Check your kitchen's GFCI outlet first—reset it. If other outlets are dead, check the home breaker panel. If power is fine elsewhere, try a different, known-working outlet with the blender. Still dead? The thermal fuse in the base is gone. For the K150, this is not a user-serviceable part. You need to contact KitchenAid for service or replacement.
IF THAT DIDN'T WORK: If you confirmed power to the outlet and the unit remains dead, the internal wiring or the main power switch itself has failed. Again, this requires disassembly of the base motor unit, which is a job for a technician.
HEADS UP: These units lack a reset button on the outside. If it trips internally, it's done. Using extension cords or sharing an outlet with other high-power appliances can cause the initial overload.