Have you tried a power off (unplugging form the mains for a few seconds)?
From results of a couple of searches (which I assume you would have done for yourself) I see there are comments about main board failure:
http://www.justanswer.co.uk/tv-repair/8nijv-matsui-tv-dvd-player-model-no-m26dvdb19-tv-either.html
You may be able to source a new main board (Gooogle, EBay, etc., ) or probably better, a new (decent branded) TV, not badged Chinese tat. John Lewis or Richer Sounds seem to offer decent warranties.
wefqgw, January 2018
