I have my TV and I want to watch a dvd. Its all plugged in and the scart plug is in etc. The picture is up there, playing normally. THERE IS NO SOUND and no, the mute button is not on!

The other point to note is that there seems to be no TV signal. I have checked the aerial plug and it seems fine. Any suggestions?

Is there something I can do to eliminate other possibilities?

First - what's a "scart plug?"

Second, please describe how you have connected the DVD player to the TV. Are you using a coax connection, RCA cables, S video, or what? Be specific.

Finally, please confirm that your system does not use any other components and you always play sound through the TV speakers, and there is no external stereo system.

Try something other than Scart for a test.
Here is Scart:
What is SCART connector? - a definition from Whatis.com

And:

http://www.hippy.freeserve.co.uk/scart.htm