Yes there is a light showing. It blinks then goes solid.
It has no on or off switch or button so we have left it on till it goes to sleep. It can turn back on by hitting any button on the remote. While trying to repair I have unplugged and plugged back in.
It is plugged into the wall with the provided cables.
I have bought a strong HDMI cable to see if that worked but it did not.
I don't have another tv so I have not tried that but can take it to a friends.
It worked since I bought it and then one day stopped. It seems to try to go on with the bouncing Roku but then goes to no signal.
I have attached photos.It says incompatible video signal and to check the out put. But nothing changed on my end.