Erratic touch screen iPhone 5

Sounds like this could be caused by a few different things.

1. Software, IOS is awful at calibration, even after a week or 2 problems can arise that weren't there to begin with.

Try reseting the device by holding both power and home buttons until the screen has gone black and the apple logo has appeared. Backing up and re installing IOS may help resolve this issue as well.

2. Shorting, any ESD (Electro Static Discharge) can cause the digitizer in the screen to act strangely i.e. ghost clicks and unresponsiveness.

Open the device and check that no screws are out of place, also check the flexes for any damage.

3. Faulty Hardware, the part that you have been supplied may be defective.

If none of steps 1,2 help contact the supplier of your screen and get them to swap a new screen with the faulty one you have been given.

Hope this helps :P

My phone does this as well, but I've not replaced anything in it. My phone has operated perfect for the entire 24 months since I got it off my launch day order. I'm going to try a battery first in case it is somehow causing this. My battery is discharging at an accelerated pace these days and sometimes it charges extra slowly too. Also, my phone acts normal for about the first 10 minutes of usage each day and then after extended periods of non-use throughout the day as well. As for my screen, it acts like an ESD issue. I'll even see red and blue grid lines on the screen when it starts acting up. I hit the power button then immediately hit the home button and swipe it open. It will then give me about 10 seconds of regular usage before it acts crazy again. I've already bought a new phone as I can't go without, but I hope to get this one fixed and hang on to it as well.

I had bought an I Phone 5S. Two days later the screen started behaving erratically. I thought maybe it was a software problem so I took it back to the store where I bought it they guided me to an apple care centre. They told me that it was the hardware problem. I had got a defective product. They helped me out with the procedures and got a replacement for the defective product.

I've seen this problem a lot with new screens. They can often be of poor quality and have a bad digitizer. Return the screen and order another. Maybe try to disconnect, clean, and reconnect the flex cables first.