the laser on my detect won’t turn on anymore, the vacuum works but the green light is out

Diagnosis

The Dyson V15 Detect utilizes a specialized Fluffy Optic cleaner head that relies on a precise electrical handshake between the main vacuum motor and the head's internal laser diode. When the vacuum functions (suction is present) but the green laser light is absent, the issue is almost never a "burnt out" bulb, as these diodes are rated for thousands of hours. Instead, the failure typically stems from a break in the electrical continuity at the connection points or a physical obstruction blocking the light path. Specifically, fine particulate dust and microscopic debris often migrate into the gold-plated contact pins located at the neck of the cleaner head. Because the laser requires a consistent voltage to trigger the "Detect" mode, even a thin film of non-conductive dust on these pins can prevent the circuit from completing. Alternatively, a buildup of static-charged lint can coat the laser aperture lens, making the light appear "off" even when the diode is active. You can confirm a connection issue if the laser flickers momentarily when you wiggle the cleaner head joint while the machine is powered on.

How to Fix It

To restore the laser functionality, you must perform a deep clean of the electrical interface and the optical lens. Follow these steps precisely:

1. Power down the V15 and remove the battery pack if you have the screw-in version to ensure no current is flowing during cleaning.
2. Detach the Fluffy Optic cleaner head from the wand by pressing the red release button.
3. Inspect the gold contact pins on the neck of the head and the corresponding pins inside the wand. Use a cotton swab dipped in 90% Isopropyl Alcohol to gently scrub the gold plates. Do not use water or household cleaners, as these can leave a residue that inhibits conductivity.
4. Locate the two quarter-turn fasteners on the underside of the cleaner head. Rotate these counter-clockwise to remove the soleplate.
5. Once the soleplate is removed, locate the laser aperture (the small clear window). Use a can of compressed air to blast out any trapped dust. If a smudge remains on the lens, use a dry microfiber cloth—do not use paper towels, as they can scratch the optic.
6. Reinstall the soleplate, ensuring the fasteners are locked tight.
7. Reattach the head to the wand, ensuring you hear a distinct "click." Power the machine on and select the "Eco" or "Auto" mode to trigger the laser activation.

If That Didn't Work

• Check the Wand Connection: If you are using an extension wand or a third-party attachment, the laser may not trigger. Ensure you are using the original Dyson V15 wand. Inspect the interior of the wand for any bent pins or debris that might be preventing the head from seating fully.
• Hard Reset the Logic Board: Occasionally, the V15's onboard computer fails to recognize the attached tool. Power the vacuum off, remove the battery for 60 seconds, and then re-insert it. This forces the machine to re-scan the attached peripherals upon the next power-up.
• Test with a Different Head: If you have access to another V15, swap the Fluffy Optic head. If the laser works on a different machine, the diode circuit inside your specific head has suffered a hardware failure (likely a severed internal wire from overheating or impact) and the entire head assembly must be replaced.
• Inspect for "Ghosting": In extremely bright rooms with direct sunlight hitting the floor, the laser may actually be on, but the ambient light is washing it out. Move the vacuum into a dimmed room to verify if the green light is truly off or simply overpowered by external lighting.

Heads Up

• Avoid using abrasive chemicals on the laser lens; a single scratch can refract the beam, causing the "stripe" of light to appear distorted or dim.
• Ensure the Fluffy Optic head is only used on hard floors. Using it on low-pile carpets can force debris into the laser housing, leading to permanent optical blockage.
• Periodically clean the gold contact pins every 3-4 months to prevent oxidation and maintain the "handshake" between the tool and the motor.
• If you notice the laser flickering, check the wand joint for any cracks in the plastic; a hairline fracture can cause the internal wiring to lose contact during movement.