Cordless vacuum will not power on, battery LEDs flash briefly then go dark

Safety first: Switch the vacuum OFF, remove the battery pack from the machine, and disconnect the charger from the mains before inspecting anything.

• Check battery seating: Remove the battery and reinsert it firmly until it clicks. A partially seated Numatic battery can cause brief LED flash then shutdown.
• Clean contacts: Inspect the metal contacts on both the battery and the vacuum body. If you see dirt, dust, or light corrosion, gently clean with a dry cloth. For stubborn oxidation, use a cotton swab lightly dampened with isopropyl alcohol and let it dry fully before refitting.
• Test with another battery (if available): If you have a second Numatic cordless battery (same series), try it in the vacuum. If the machine powers normally, the original battery pack or its BMS is likely faulty.
• Check for bent pins: Look closely at the battery connector pins on the vacuum. If any are bent or pushed in, do not force the battery. Bent pins can short the pack and damage electronics. This usually requires professional repair.
• Charge and retry: Place the battery on the official Numatic charger until it reaches full charge (all LEDs solid or as per manual). Refit and test again.

If the vacuum still will not power on and the LEDs only flash briefly, the battery pack or control PCB may need replacement. Contact a qualified service technician if you are not comfortable working with battery systems.