@Charles_G Sniff it. Does it have a chemical stench to it? Why am I asking this? Typical cause of death for these is their internal power supply failing, mostly due to cheap capacitors leaking and failing.

What do you do now? If it's under warranty, return it. If you're desperate and don't care much about potential fire hazards from running slightly too cheap electrical equipment in your house 24/7, repair it - normally replacing the capacitor(s) does the trick, but it's just a matter of time before the other one from the adapter pair dies the same death.