Nikai5000 tv smarte Performs the work for half an hour

If your TV is still not working after disconnecting it from power and waiting a few hours, then it is likely that the files that were deleted were essential to the TV's operation. In this case, it is likely that you will need to have the TV serviced by a qualified technician.

1) Make sure nothing is covering the infared receiver spot on the TV. Might be something that simple.
2) Try a "universal" remote -- under $10 many places.
3) If you haven't done this already, unplug TV for a minute or two and when you plug it back in, may reset.
4) Contact manufacturer via their web site for help.

Did you reset the router? If you did or had a power failure, many times the address your smart TV is looking for has been changed in the router. Go back in to the TV's wireless setup and search for networks again and log back in.

Most likely a bad firmware flash, was the tv connected via WiFi or by ethernet cable? I see this a lot when people update over WiFi on these Samsung TV's, i have about a half dozen dead mainboards from repairing them. The only option you have now is to find a used working mainboard and swap it out.

when i start tv 1minit picture show 1minit after no picture but sound have

There's a circuit board under a metal cover that needs to be replaced. This board conrtols the picture.

If you have tried using different input devices, looked for loose contacts
in power outlet, RC Jack, cable and connectors, the TV might need service.

I just left the TV off and it must have reset itself. It did it twice. First time it was OK after half an hour. Second time it was nearer an hour.

Thanks