DIAGNOSIS A foreign object (pebble, jewelry, twist-tie) is lodged in the main roller cage or the debris extractors are jammed.
FIX Turn the robot over, remove the bin, and pull out both roller brushes. Inspect the ends of the rollers and the chambers they sit in for stuck debris. Clear anything you find. Manually spin the rollers—they should move freely.
IF THAT DIDN'T WORK Check the main brush chamber itself. Small objects can get past the rollers and jam the impeller fan inside the suction path. You may need to shake the robot upside down or use long tweezers.
HEADS UP This noise can also mean a bearing in the roller end cap is failing. If rollers are clear and spin freely but the noise persists, replace the rollers—the end caps are part of the roller assembly.