Symphonic WF27F4 (an old tv??) How to restore the video which is sometimes just a horizontal bar or line, and if you hit a good wallop it may recover the picture for an hour, a day, or a week until it dies again.

Hit your TV lightly on left side or right side or on top & then observe ..........you will get normal picture or it comes & again it goes....if it is happening like that then following is the situation..........after 4 or 5 yrs in some TVs on main board (also on circuit board that is fixed to CRT TUBE ) at some soldering joints crack develops....then due to loose contact picture becomes small in size or disappears or rolls ...........when we hit that lightly then those loose contacts joins temporarly & again picture appears for some time............so solution is ......TV main board should be observed carefully & most of the joints should be re-soldered.......only a good service engineer can do that........even after hitting TV lightly if there is no response then main board has to be checked completely........in your case iam sure it is loose connection problem.........joints should be re - soldered ...100% it works again................this problem cannot be solved by user unless user has idea about components( resisitors, transisitors, diodes,...etc) , have soldering iron , multimeter & other tools....................so contact good TV service engineer

It's junk...just junk