LED indicator shows four red flashes when trigger is pulled, vacuum does not start

Safety first: Remove the battery pack before inspecting contacts. Do not short the terminals.

• Inspect contacts: Examine the metal contacts on both the battery pack and the vacuum's battery bay. Look for bent pins, corrosion, or heavy dirt.
• Clean contacts: Use a dry, lint-free cloth to wipe contacts. For light oxidation, use a pencil eraser gently, then wipe away residue. Do not use liquids or abrasives.
• Check battery fit: Ensure the battery slides in fully and clicks into place. A loose fit can cause communication errors.
• Try another battery: If available, test with a known-good genuine Black+Decker battery of the same series. If the error clears, replace the original pack.
• Inspect housing: If contacts are physically damaged or loose inside the vacuum, the main housing or control PCB assembly may need replacement by a technician.