Touch Disease: Cause and Solution

Screen problems are common with touch screen phones. It may be physical problem, like a visible cracked screen, or this what we called Touch Disease. 
Touch Disease will make your iPhone develop a small grey flickering band at the top of the screen, always just below the phone speaker regardless of device orientation. The clearly abnormal band can be sporadic, may respond to torquing or pressing on the device.   

🤚What causes it?
Touch IC chips on the phones' logic board break away partially, making for intermittent electrical connections. This in turn causes the above-mentioned symptoms. Experts say the Touch IC chips break away from the board during everyday use, such as when a phone flexes slightly when stored in a trouser pocket.

🤚Temporary Solution
Applying pressure to the screen, or twisting it slightly, can appear to fix the problem. Since it forces the Touch IC chips to re-establish full contact with the logic board. However, this is not a permanent solution and the problem will return. Remember, this problem is not an issue with the screen or its digitiser (the layer beneath the screen that registers touch), thus replacing the screen will not solve the issue.

🤚What to do after?
If your device is still within its guarantee period then take it to Apple, where they'll almost certainly either swap the logic board for a replacement, or swap the entire phone for a replacement.