To all those who have this problem and who will have this issue in the future, I finally now have the solution which can be done all by yourself. Firstly, two things tend to happen with some samsung dvd players and tvs. One, they either switch off all on their own, or two, the volume goes down to Volmin all on its own. To fix this, search no further! What you must do is open up the case of the dvd player by unscrewing the 6 screws at the back. Then lift off cover. Then with a small flathead screw driver flip off the front facia touch panel. You will see two small brown ribbons. You must detach them both by pulling them out of its tiny socket. One of them is a sensor for the On/Off switch. The other is a sensor for the volume up/down switch. Once you have taken those two ribbons off (at either end), put the front facia clippe back in place. Then put the top cover back on with the 6 screws. Thats it! All your sound problems solved.
Ive spent countless hours searching, many times dismantling the dvd player, and have FINALLY come to this solution. Believe me it works, anyone can do it. And it will save you lots of money by not sending it to a repairman. I hope this helps many people and saves them hours of frustration!!