Robot vacuum shows E5 and refuses to start; often occurs when placed on thick carpet or thresholds.

Safety first: Turn OFF the robot and place it upside down on a soft cloth.

• 1. Locate cliff sensors: On Amazon Basics robot vacuums, cliff sensors are usually small windows on the underside near the front edge.
• 2. Clean sensor windows: Use a soft, dry microfiber cloth to wipe each sensor window. For stubborn dirt, slightly dampen the cloth with water (never spray liquid directly on the robot) and dry immediately.
• 3. Test on different flooring: Move the robot to a lighter-colored, non-reflective floor (e.g., light tile or wood) and try starting a cleaning cycle. Very dark carpets can sometimes trigger false cliff readings.
• 4. Check for physical damage: Inspect the sensor windows for cracks or deep scratches. Damage can cause misreadings.
• 5. Advanced check: If comfortable, remove the bottom cover and verify that the cliff sensor harness is firmly connected to the main PCB.
• 6. If E5 continues: One or more cliff sensor modules may need replacement. This requires disassembly and should be done by a technician if the unit is under warranty.