Power Source

If you use a laptop computer, and your power cord seems to have gone out, try this:  unplug the cord from your laptop, and also from the electric socket.  Let it be unplugged for 2-3 hours minimum, and for sure, until the transformer is room temperature.

I have done that several times with the power cord for my laptop...

Batteries

One of my many remote controls was not working properly.  I groused and grumbled for a couple of days, then did the simple thing: I changed the batteries.  Isn't it amazing what a difference a fresh set of batteries makes for electronics?