Answer to: Black Vertical Lines on LCD assembly after replacementI had this issue after re-assembly of front screen on an iPhone 5S. The symptom is light vertical bars that are obvious when screen is bright. In some cases, there may be horizontal bars creating a plaid effect. The screen also does not respond to touch input, making it impossible to shut down, apart from holding sleep and home button. (If the home cable is connected) I was worried at first that I had damaged the ribbons or pins on the pins on the three connectors. However, I found that I just needed to carefully but firmly press down the connection points until they were solid. I believe the top most connector is the digitizer, which is the easiest one to come lightly unseated while the screen is detached. I had the effect happen twice during the rear-facing lens cleaning run I was doing and was able to fix it both times.