the trigger on my v12 feels sticky and sometimes stays on after i let go, how do i fix that?

Diagnosis

The "sticky" trigger on the Dyson V12 Detect Slim is typically caused by a buildup of fine particulate matter or microscopic debris that has bypassed the filter and migrated into the trigger housing. Unlike the V11 or V15, the V12 uses a more compact trigger assembly; when dust mixes with humidity or small amounts of cleaning residue, it creates a tacky paste that increases friction against the internal return spring. This friction prevents the trigger from snapping back to its neutral position immediately upon release, causing the motor to continue running for several seconds or stay on indefinitely. You can confirm this by observing the trigger's travel distance: if the button feels "mushy" or doesn't return to the exact flush position against the chassis, the internal spring is being obstructed by debris or the plastic pivot point is contaminated.

How to Fix It

To resolve this without dismantling the entire chassis, you need to clear the mechanical path of the trigger using a combination of pneumatic pressure and a non-conductive lubricant.

1. Power down the unit and remove the battery pack by unscrewing the three screws (located at the base and side) to ensure no electrical shorts occur during cleaning.
2. Position the vacuum handle vertically over a waste bin.
3. Using a can of high-pressure compressed air (ensure the nozzle is the thin straw attachment), insert the tip into the narrow gap between the trigger button and the main plastic housing.
4. While spraying short, 1-second bursts of air, rapidly cycle the trigger (press and release) 20 to 30 times. This vibration and air pressure help break the "bond" of the sticky debris.
5. Apply a single drop of electronic-grade contact cleaner (such as DeoxIT) or a tiny amount of dry PTFE lubricant into the trigger gap. Avoid using WD-40 or oil-based lubricants, as these attract more dust and will make the problem worse over time.
6. Cycle the trigger another 10 times to distribute the lubricant across the pivot point.
7. Wipe away any excess residue from the exterior of the button with a microfiber cloth dampened with 70% isopropyl alcohol.
8. Reinstall the battery and test for a crisp, immediate shut-off.

If That Didn't Work

• Manual Pivot Clearing: Use a thin plastic probe or a toothpick wrapped in a lint-free cloth dipped in isopropyl alcohol. Gently slide it into the gap around the trigger to manually scrape away any visible grime or hair that may have wound around the trigger axle.
• Spring Tension Check: If the trigger remains loose, the internal return spring may have fatigued or slipped. While the battery is out, firmly press the trigger all the way in and hold it for 5 seconds, then release it sharply. This can sometimes reseat a displaced spring.
• Housing Compression: Check for any cracks in the plastic casing around the trigger. If the plastic has warped or cracked, it can pinch the trigger mechanism. If a crack is visible, a small amount of epoxy or a tight-fitting plastic shim may be required to prevent the trigger from catching on the housing.
• Component Replacement: If the trigger feels "crunchy" or physically snaps, the internal plastic lever has likely fractured. In this case, the trigger assembly must be replaced. This requires a full teardown of the handle section to access the internal switch.

Heads Up

• Never spray liquids directly into the trigger housing; always use a cloth or a specialized electronic cleaner to avoid shorting the PCB.
• Check your filter regularly; a clogged filter increases internal pressure, which can actually push more dust into the handle assembly through the air vents.
• Avoid using the vacuum on wet surfaces or damp carpets, as moisture accelerates the formation of the "dust paste" that causes trigger stickiness.
• If you use the vacuum in a high-dust environment (like drywall sanding or workshop use), blow out the trigger area with compressed air once a month as preventative maintenance.