How can i fix my samsung home cinema dvd player? model HT-TX35?

Hi i dont know if you can help me but i have the samsung HT-TX35 home cinema system, and the dvd player is not working? It just playes a distorted sound and sometimes a distorted picture or no picture at all. the dvd's im am playing have definatly worked previously. I have checked all the wires they are fine, i have tried lots of dvd's that have definatly worked before, i have checked the manual and have reset it but it still will not work? We sent this dvd player off to samsung last year, we only had it for a couple of weeks and the dvd player wouldnt work. They had it for about 3 months, it came back three times, twice it didnt work, the third time they had scratched the back, but we had had enough and just kept it because finally the dvd player worked. As you can probably tell we do not want to send it back again, as we will need the dvd player for xmas. please can you help?