TV has sound, but no Picture

Change input device to some other like a DVD player and see.
Switch off TV, switch off power, remove plug and wait for 48 hours and retry.
If problem persists, call in a qualified service technician.

Are you routing the video into your reciver from the dvd player? If so route the video directly into your tv. It won't fix the initial problem but you will get picture and sound to watch dvd movies.

Try holding the power button in on the receiver until the picture goes away then turn it aloose it will reboot and your sound will usually come back. If you had rather and can get to it unplugging it from the electric outlet, the receiver, does the same thing.

check your scart male connecter ends are pushed all the way in.

i guess there a built in dvd player on the set and it could play most DVD format.
but if you wish to use another dvd player
hook up the dvd on the tv
video output (DVD) to video input (TV)
audio output to audio input
the find the auxiliary button from either the tv or dvd

on you tv must be a button "video/tv",you have to push this many times to find front, back or video1 or video2 (depent were you plug the dvd)and there is were supost to work. no on channel 3 or 4

Probably need the TUNER either fixed or replaced.

before you can watch a recorded DVD on another DVD player you must finalize the disc. to finalize the disc put the recorded disc into the DVD recorder, when the DVD loads it will show the titles that are recorded on the DVD on the screen
push the stop button it is the button with the square on it. the screen will go blank or it may let you watch whatever tv channel you are on if you have your tv ran through the recorder, push the setup buton a new screen will come up, with the arrow down button scroll down and highlight disc edit, press ok another screen will come up, with the arrow down button scroll down and highlight "finalize", press "ok" it is the button in the middle of the arrow keys
scroll up and highlight "yes" press "ok" the recorder will finalize the disc and it can be watched on any DVD player, just remember when you finalize a disc you cannot add anything else to the disc.

I call a tech in. It could be quite a few issues.

Using the remote control, push the left arrow until display shows Coax1 (or 2, depending on your setup), then push the up arrow to set it to TV/SAT.
Conversely, depending on your setup, you can push the left arrow to display Comp1 (or2) then push the up arrow to set the correct video setting-- DVD/LD I assume.