Why is the switch no longer transmitting power through the plug?

Hi @wattdee ,

What is the model number of your WeMo?

If it is a F7C027 can you hear a "click" coming from the switch when you try to turn it on?

If so this is the relay in the switch connecting the power to the outlet. If there is a click and there is no power then the relay contacts may have burnt out and the relay will have to be replaced.

If there is no click then either the relay coil is faulty or it is not being operated when required.

The switch would have to be opened and the problem further diagnosed

Here’s a link to the ifixit Belkin WeMo Switch Teardown guide which may be of some help.

As this device switches potentially lethal voltages, if you don’t know what you’re doing when testing electronics where these voltages are present then DON’T. Leave it to the experts.

Hi @wattdee ,

At least hearing the relay operate indicates that the signalling system from the controller to the switch is working.

Most of the components in the switch are there to get the relay to operate and release on command. When operated its’ contacts switch the power from the wall outlet through to the output of the switch

As I said the contacts of the relay may have burnt out or there is an open circuit in the voltage path from the supply input, through the relay contacts to the output from the switch.

You can use the teardown to open the switch and then use an Ohmmeter to test the path of the voltage from the input to the relay contacts and then from the relay contacts to the output. If this tests OK then it proves that the relay contacts are faulty and the relay needs to be replaced, as it cannot be repaired.

This is the safe way to test it as it is totally disconnected from the power

Here’s an image taken from Step.9 in the teardown that shows the relay. (highlighted by red box)

(click on image to enlarge for better viewing)

The relay is a HF3A 005 HTF.

Here’s a link to just one supplier. It is shown only to give an idea of what it looks like and the cost of the part. There are other suppliers online that may suit you better. Just search for hf3fa 005 htf.

You will have to unsolder the old relay from the circuit board and then solder in the new one.