Playing DVD disc on television

[brianp]

I am having a problem playing the disc of my film on the television. At first I found it would play on my two small televisions but not on the larger one. After making some alterations but I'm afraid I can't remember exactly what I changed, I found that it wouldn't play on any of the televisions. Could anyone tell me what process I have to go through to get it to work as I think it must just be a matter of setting it correctly.