Vacuum powers on but shuts off randomly; display shows E9 or nine red flashes; occurs more often when moving the handle.

Safety first: Remove the battery pack before working on the handle or trigger area.

• Inspect the trigger: Check for physical damage, looseness, or misalignment. Ensure it returns smoothly when released.
• Check for debris: Use a soft brush to remove dust and debris around the trigger opening that may interfere with movement.
• Wiggle test: With the battery installed, gently move the handle and trigger while the vacuum is running (avoid opening the unit while powered). If the unit cuts out with slight movement, an internal connection is likely loose.
• Internal inspection (advanced): If you are comfortable and the design allows, remove the handle screws and carefully open the housing to inspect the trigger switch and wiring harness. Look for loose connectors or broken solder joints. Re-seat any loose connectors firmly.
• Replace faulty switch: If the trigger switch feels spongy, sticks, or shows signs of burning, it should be replaced. This may require a compatible Tristar handle/trigger assembly.