Headphones For Portable Dvd Players Why Is My Portable DVD Players Volume On The Fritz?

Why Is My Portable DVD Players Volume On the Fritz? - headphones for portable dvd players

I have used a portable DVD player and it worked perfectly. So I let my sister borrow the volume and started off. The first volume is good, but after 30 seconds, or drops so it is now with built-in speakers and headphones, if you have something internal. So can someone tell me what is wrong and what can I do to fix it.