Israel, It sounds like it is a bad screen. Check to see if the connectors are bent in any way. Every once in a while some replacement screens are just DOA when they arrive. Hopefully whoever you bought it from will send you a replacement.
The other thing that I encounter a lot is the frame will be dented and cause the screen to sit high. I would check it carefully and make sure nothing is pushed in. If it is I just take a screwdriver and a rubber mallet and pound it out
Bad headphone jack, check to make sure there is nothing inside of the jack that could be blocking the connection. Try another pair of headphones and see if they work.