Cordless vacuum shows E7 and will not charge when placed on the Tower charging dock or plugged into the charger.

Safety first: Disconnect the charger from the mains before inspecting connectors. Do not attempt to open the charger casing.

• Step 1 – Check mains outlet: Test the wall socket with another device to confirm it has power.
• Step 2 – Inspect charger and dock: Look for damage to the Tower charger cable, plug, or docking station. If the cable is frayed or the plug is burnt, stop using it immediately and replace the charger.
• Step 3 – Clean charging contacts: On removable batteries, clean the metal charging contacts on both the battery and dock/charger with a dry cloth or isopropyl alcohol on a cotton swab. Allow to dry fully.
• Step 4 – Check charger LED: Plug in the charger without the vacuum. Confirm the indicator LED behaves normally (refer to your manual). Then connect the vacuum or battery and see if the LED changes to charging status.
• Step 5 – Try another compatible charger: If available, test with a known‑good genuine Tower charger of the same voltage and connector type.
• Step 6 – Replace faulty part: If E7 persists with a known‑good charger, the internal charging PCB or battery is likely faulty. Replace the Tower charger / docking station first; if still unresolved, replace the Tower lithium‑ion battery pack or charging PCB module (for fixed‑battery models).