The vacuum will not power on; battery LEDs remain off when the trigger is pressed.

Safety first: Turn the vacuum OFF, remove the battery pack from the handle or base, and disconnect the charger from the mains before inspecting anything.

• Check Battery Charge: Insert the battery fully until it clicks. Press the battery test button (if present) and confirm the LEDs light up. If no LEDs light up, place the battery on the Nilfisk OEM charger for at least 3–4 hours and verify that the charger LED shows charging.
• Reseat the Battery: Remove and firmly reinsert the battery pack. Ensure there is no debris in the battery rails or contacts on the handle. Clean the contacts gently with a dry cloth.
• Test the Trigger: With a known-good, charged battery, squeeze the trigger. If the battery LEDs light up but the motor does not start, the trigger switch or main PCB may be faulty.
• Try a Second Battery/Charger if Available: If another Nilfisk battery works, the original battery pack or its BMS is defective. If neither battery works, suspect the main PCB or trigger assembly.
• Do Not Bypass Safety Circuits: If the unit still will not power on, the main control PCB or internal wiring harness may be open. At this point, professional service is recommended.