Robot mower shows E4 and refuses to start; often occurs when placed away from the charging station.

Safety first: Turn the mower OFF and unplug the charging station power supply before handling wires.

• Check charging station LEDs: Most Stiga stations have an LED indicating loop status. A steady green usually means OK; flashing or off indicates a loop fault. Refer to your model’s manual for exact LED meanings.
• Inspect boundary wire connections: At the charging base, open the terminal cover and ensure both boundary wire ends are firmly clamped and not corroded. Trim and re‑strip the wire ends if needed.
• Look for visible wire damage: Walk the perimeter and check for cuts from garden tools, pets, or rodents. Pay special attention to flowerbeds, paths, and edges.
• Use a wire break locator (optional): A simple AM radio or dedicated loop tester can help locate breaks by following the signal along the wire.
• Repair breaks: When a break is found, strip both ends and reconnect using waterproof gel‑filled connectors approved for boundary wire.
• Check power supply: Ensure the station’s power adapter is plugged in and the outlet works. Replace the adapter if the station has no power.
• Test: Once the loop LED indicates normal operation, place the mower in the station, power it ON, and clear the E4 error.