1) make sure the power is on. a lot of boxes show a lit LED indicator even when it isn't on (amber or red) and on (green, bright blue, yellow) so it can fool anyone to thinking it is on when first plugged in (yes, i too fell for it, i always thought no lamp = off lit lamp = on go figure why they want it constantly lit)
2) if the box has no front panel buttons or no power button make sure the batteries in the remote are inserted correctly and get real batteries, not the ones which come with the remote. one of my boxes had the batteries provided leaking acid.
3)Box may be faulty, a few end up bad out of the box
4) make sure the outlet you're using is NOT a GFCI (Ground Fault Circuit Interrupter) or is protected by one. i cannot count how many times the darned thing pops even when no load is present and takes half my house with it, since it's got about one end hooked through such a circuit. such an outlet will have a 'reset' and 'test' button like a small circuit breaker and be in a bathroom or kitchen area. the one you're using could have one which powers the TV but the other outlet in the same panel can be protected by a GFCI which has tripped leaving you to wonder why the TV works but not the box.