After replacing rear camera, still black screen

I bought a phone that had the only thing wrong with it listed as a image shutter problem when attempting to take a picture. Naturally, I purchased a new camera, restored the phone, updated the firmware, and reseated the new camera onto the connection. It still will not work. For one distinct second I got the flashlight app to work but then nothing else. The connection is good, the camera is good I have tested it on other iphones, and I even cleaned the connection with rubbing alcohol to see if there was any corrosion. What am I missing?