I am looking for someone who can help me understand how too capture vhs to my computer using this product. I tried it on my dvd player and it works fne, but when I use the vhs side it only has the sound no movie in preview. I hooked it up like it should be, but still no luck. I read one issue that when dvd & vhs is a combow it will not work? SO do I need just a vhs player alone?