DIAGNOSIS Debris is jammed in the base's suction motor or the robot's dustbin port. Common culprits are large hair ties, pebbles, or chunks of pet litter.
FIX Unplug the base immediately. Remove the dust bag and inspect the bag port. Shine a flashlight inside and look for blockages. Use long-nose pliers to remove any foreign object. On the robot, empty the dustbin and check the rubber flap valve for obstructions.
IF THAT DIDN'T WORK The grinding is from the base's internal impeller. A small object has passed into the motor housing. This requires disassembly to clear; contact Shark support.
HEADS UP Always do a quick floor sweep for large objects before running the robot. The self-empty system can't handle anything bigger than fine dust and small debris.