Video stopped working. I get audio but no picture.

If you've switched on your TV and the sound comes through fine, but you're not seeing any picture; there are 3 potential issues. No video with normal audio on a Smart TV will the result of one of the following issues: A connection issue; the most common problem. ... An issue with the device connected to the TV
https://www.samsung.com/au/support/tv-audio-video/my-tv-has-audio-but-no-video/

The Video (Picture) is SEPERATE from the Audio component of the TV. One can work when the other has gone south. From what I see, the Audio controller board may have been damaged somehow and needs to be replaced. Contact a serviceman for details.

When you plug the AV cables into the receiver make sure that the channel that it is plugged into is selected on the front of the receiver. Also note that the receiver should have a monitor output that should be plugged into the TV and the TV input must be selected on the TV.

Most of these TVs show a blank screen unless they are receiving a sinal?

Select AV-1 or some thing in TV and plug DVD recorder Video-Audio output in AV-1 input of TV, playback any DVD and confirm its picture and sound in TV. Press Stop button of DVD recorder to stop playback.
Now plug Video-Audio output of VCR in DVD recorder input and select AV Input in DVD recorder, insert VHS tape in VCR and playback it and confirm you get VHS picture and sound in TV via DVD recorder.
Hookup between TV, DVD recorder and VCR is completed.
Playback VHS tape in VCR, Insert blank DVD disc in DVD recorder and press Record while you see VHS tape picture in TV.
Hope this info will help you.

Connect the DVD player audio with digital coax into the digital audio connection as you described and the DVD video directly to the TV. Now switch the input mode on the receiver to DVD. Then switch the video output mode on the TV to correspond to the input you plugged into. Any source in 5.1 dolby digital or dts should now work properly and have picture too.

Yeah no color coz its black and white. Color coding commonly yellow wire for video, red and white wire for audio. It should also be from DVD to TV, video out and audio out going to video in and audio in. And switch the TV to play video and the audio inputted. Maybe TV/Video Switch or button.

Hope it helps

red, white plugs are for left and right audio..... yellow is video, your tv may not have a video plug, just speaker plugs 

I don't know how you connect the unit to the tv.
Let's just start on basic:
composite video/audio(yellow-video, white/red-audio) connect to TV composite video/audio input behind the TV.
If the audio works but no picture,try to use another video input behind the tv.if that still doesn't work,use a different video cable!
Good luck!