No Loop Signal - Blue LED Blinking on Charging Station

Common Medium Difficulty Low to High Cost 10-90 Minutes
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Problem: The charging station shows a blue flashing LED light and the mower reports "No loop signal" or "Weak loop signal". The Automower cannot start or returns confused to the charging station.

Problem Description

The charging station shows a blue flashing LED light and the mower reports "No loop signal" or "Weak loop signal". The Automower cannot start or returns confused to the charging station. This is one of the most common installation problems and can occur with both new installations and existing systems.

Affected Models: All wired models (305, 310, 315, 320, 405X, 415X, 420, 430X, 440, 450X)

Possible Causes

  1. Cable break in boundary or guide wire (most common cause) – Damage from garden work, spade, or scarifier
  2. Charging station without power supply – Power adapter not plugged in or fuse blown
  3. Poor connection at cable terminals – Oxidation or loose fit
  4. Cables swapped or incorrectly connected – Confusion of AL/AR or guide wire
  5. Defective circuit board in charging station – Electronic defect (rare)

Step-by-Step Solutions

Solution 1: Check Power Supply

Time Required: 2 minutes

  1. Check if the power adapter is plugged in (outlet and charging station)
  2. Check the house fuse or circuit breaker
  3. Check the LED on the charging station:
    • Green = Everything OK
    • Blue flashing = Power OK, but cable problem
    • Yellow = Weak signal
    • No light = No power supply
  4. With blue flashing: Power supply is working, there is a cable problem
LED Diagnosis: The blue flashing means the charging station has power but does not detect a closed cable signal. This indicates a cable break or poor connection.

Solution 2: Remake Cable Connections

Time Required: 10 minutes

  1. Open the cable terminals at the charging station
  2. Remove the cable from the rubber grommet
  3. Cut off 1-2 cm of cable and strip fresh (5-7 mm)
  4. Reinsert the cable into the terminals (tight fit is important!)
  5. Pay attention to correct polarity:
    • AL = Outer wire Left (boundary wire)
    • AR = Outer wire Right (boundary wire return)
    • GUIDE = Guide wire
  6. Press the terminals firmly closed
  7. LED should now light green
Tools Needed: Wire stripper, side cutters, screwdriver if needed
Important: Oxidized cable ends frequently cause signal problems! Always cut off a piece and strip fresh. Make sure no copper strands are outside the terminal, as this can cause short circuits.

Solution 3: Locate Cable Break

Time Required: 30-60 minutes

If the cable is correctly connected but the LED continues to flash blue:

  1. Use a cable detector or AM radio (AM/MW radio on 570-1600 kHz) to find the break
  2. Typical break locations:
    • Driveway (run over by car)
    • Lawn edges (edge cutter)
    • Flower beds (spade, excavation work)
    • Tree roots
    • Areas with scarifying work
  3. When break found: Repair cable with original connector
  4. NEVER simply twist cables – always use waterproof connectors!
Tip: Start the search at the most likely locations – where you recently did garden work. An AM radio makes a loud noise along the cable that suddenly stops at a break.

When Should You Consult a Professional?

With a break in the installed cable that you cannot locate yourself, professional help with a cable detector is often necessary. If the charging station's circuit board is defective (LED does not light at all despite power supply), it must be replaced by a specialist. Also, with multiple cable breaks, it's often better to relay the entire cable.

We offer professional cable break diagnostics with professional measuring equipment and stock all spare parts: charging stations, boundary wire, connectors, and repair kits.

Preventive Measures

  • Install cable correctly – Fix with lawn pegs every 75-100 cm
  • Observe cable depth – Install maximum 1-5 cm deep, no deeper!
  • Document cable route – Make a sketch or take photos
  • Be careful with garden work – Especially when scarifying and digging
  • Annual inspection – Check and tighten cable connections at charging station
  • For EPOS models – Regularly check support-by-wire cable for damage
Pro Tip: Mark the cable route with small stakes or spray paint on the lawn before doing garden work. This prevents accidental damage. The marking grows out again after a few weeks.

Need Help with Cable Repair?

Cable break diagnostics, original connectors, boundary wire, and complete repair kits can be found in our shop. For persistent problems, we're happy to help with professional on-site diagnostics.

Contact Us Now View Spare Parts
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