american portable dvd player .need help ......!!!!!

hi ,i am new to this ,so here goes. i bought a disney princess portable dvd player from a american seller on ebay,its been fully charged and all the set up screen works etc how ever the dvds keep sticking.i did by region 1 films for it and two of them are brand new although they are clean i dont no what the problem is ,do i need to replace the lens or the laser ,the seller hasnt yet replied to my emails  i have learnt my lesson.but need this sorted asap as supposed to be a xmas pressie for my little girl,if i cant get it fixed it means i am also stuck with region 1 dvds..!!!the model number is dpr3500-prn