The video output of my DVD player doesnt work

I had a DVD player Toshiba SD 4000. The video output doesnt work, and Im watching the movies by another output, Yx is the name of the output. I went to see an electronic and he told me that was probably that my DVD lost it program, and that I need a number to fix it, but I dont have it. Now Im watching movies real bad, the image is distorsioned in some movies, sometimes when I put VCDs it works well, but not when I put DVDs. I change to free zone already (0) but still I have the same problem. If you could give me the code, or a place where to find it I will aprecciate, or if my DVD had another problem. Thakns for all.