If the smart plug or switch can turn on/off themselves but they cannot turn on/off the devices connected to them, please refer to the corresponding product for troubleshooting. For smart switch: Note: If the appliance has the other hardware button, please keep that button the “On” status. Check if you can turn on/off the appliance manually by pressing the hardware button of the switch. Try to plug a different device into the switch, like a lamp or a light. Please make sure the wirings connection is correct and not spoiled. If you are not sure about the information, please ask for help from a professional electrician. Exchange another switch in the same location with the same wirings or install this switch in the other location to check. If the above suggestions still cannot fix the problem, please collect the following information: The picture of the wiring (noted the name of each wiring). The Model & Power consumption of the device connected to a smart switch. The light status on the switch itself. The results of the above suggestions and contact TP-Link support for more help. For smart plug: Note: If the appliance has the other hardware button, please keep that button the “On” status. Check if you can turn on/off the appliance manually by pressing the power button on the plug. Try smart plug in another power socket. Try to plug a different device into the plug, like a lamp or a light. Unplug the smart plug from the power outlet, then try gently tapping the side of the plug: pick it up and gently tap its side to a level surface. Check the link below to reset the smart home devices, then configure it again. How to factory reset the Tapo or Kasa smart plug If the above suggestions still cannot fix the problem, please collect the following information: The Model & Power consumption of the device connected to the smart plug The light status on the plug itself. The results of the above suggestions and contact TP-Link support for more help.