MK181 goes off after a few seconds

A customer has purchased a number of MK181 from us. They say “on power on the led glows dimly and fades to off during the first 5 seconds, and will not light again following this.”

Please can you suggest how to rectify.

There are no known issues with this kit.
We suspect that the kit is used on a DC voltage instead of an AC voltage.
If this is not the case, then we suspect an assembly error.
Sorry, this forum does not allow picture uploads
If you can provide LINKS (e.g. by using a free online picture base) to HI-RES and SHARP pics of your assembly (both solder- and component side)
then we can take a look and provide some feedback.