Tv has no any light

Ok, the LIGHTS are the KEY to your problem. Glad you found the switch too, a lot of people accidently turn off their TVs without even knowing it, and if it's off, the lights never light.

Since you've tried the power switch and the light did not come back on, then the Standby power supply isn't working, or the TV's microprocessor is dead and not lighting the lights.

If you have a voltmeter, then I'd check the 5 volt power supply. If you recently had a storm or something like a major power outage, inform me of that. I'd prefer a simple voltage test, but not everyone has a voltmeter in their homes, and a hardware store or a Sears store isn't nearby.