Disposal runs but makes a loud, low-frequency vibration that shakes the sink; LED flashes ten times.

Safety first: Turn off power before adjusting any mounting hardware.

• Check mounting ring tightness: From under the sink, verify that the McAlpine mounting ring is fully rotated into the locked position. Tighten the three mounting screws evenly.
• Inspect rubber cushion: Look at the rubber mounting cushion between the sink flange and disposal. If it is torn, compressed, or missing sections, replace it with a new McAlpine mounting gasket.
• Check for internal imbalance: With power off, rotate the impeller plate by hand (using a tool) to ensure it spins without catching. If it wobbles significantly, the plate may be bent.
• Test with water: Run water and briefly operate the unit. Minor vibration is normal, but strong shaking indicates internal damage.