Erratic touch screen iPhone 5

Hello,

Two weeks ago I tired to open my iPhone 5 to clean some dust from the camera.

Since then I'm having erratic response from the screen. Normally when I wake up the phone it is not responding, but if I sleep and wake up the phone immediately it works for a while. After some seconds or one minute I have the same problem.

I tried to open and reconnect the digitizer thousand of times and it is always the same. The connector it seems to be ok on the screen as well as the logic board. The flex from the screen seems to be ok too. Doing all this operations I damage the sponges from the connector.

When I couldn't solve the problem I went to a non official shop to fix it and they couldn't also. They lost one screw from the screen connectors fixation plate. Of course, it still not working well.

Now I don't know what to do. I was planning to buy a new screws set and some sponges in ebay to fix that, but I don't know if it will work.

I will try to review again the logic board but, if sometimes works and others not, do you think that it could be some resistor or capacitor lost? Do you think that I need to buy a new screen? Do you think that it could be a logic board malfunction?

Thank you very much for your help!