Screen flashes once, then goes dark. Power button does not work.

verify that you have no image on all inputs. If it remains dark, unplug it and push the power button for about one minute, then plug it back in. See if that resets your TV.

If it remains dark, use a flashlight and angle it against the screen with the TV at a station where you can hear the sound See if you can make out shadows or shapes. If you do, then it is your backlight that has failed.

Yes, it can be fixed but you have multiple problems. By the time you replace all that has to be you would be better off buying another disposable TV.

If you wish to get some details; check the site linked here. Pull up older posts. Surf the site with patience. http://electronicshelponline.blogspot.com/

What is the brand name and model number to your TV? Provide more details, please. If you wish to get some details; check the site linked here. Viewing it in "Mosaic" will make surf easy. Surf the site with patience.
http://electronicshelponline.blogspot.com/ Pull up older posts there.

Short circuited component/s at its main board. These blinks [flashes] are fault indication (Error Codes).From the number of blinks occur at one time switch ON, you can get an idea about the faulty circuit stage inside it.This will make repair easy.These are called blinking codes. Make sure about the exact number of blinking of the standby/power led, by switching On & OFF the set, for at least two times.Count it carefully.If you wish to get some details, check the site linked here.It has details about blinking codes, and fault locating, to many popular brand TVs and other devices.Viewing it in "Mosaic" will make surf easy.
http://electronicshelponline.blogspot.com/
Blinking codes details to many popular brand TVs are given.

Try this:
1) turn on the TV
2) from the remote control press MENU 2,4,7,0 then ENTER
3) tv will state on screen that it is INITIALIZING
4) when done press the front reset button.
5) should be good to go!

Replace the digital/ siene board

Hi its ok now I called out a repair guy.

Thanks Sonny

Hiya this is how i got mine to work.Manually turn on the tv.
Press and hold setup on your remote till the light comes on and stays on.
Then press the tv button then release. The light will flash then continue to stay on. 
Now press and release the power button waiting 2 seconds before you press it again until your tv switches off.. you may have to press it for awhile.
Once your tv cuts off press the mute button and now your remote is set for your tv.