Touch screen and dead pixel test for Android

Updated October 2026. About 4 minutes to read.

Screen faults are easy to miss in a shop and expensive to fix. Two problems matter most: parts of the glass that do not feel your finger, and pixels or areas that show the wrong colour.

Touch: dead zones and ghost touches

1. Turn on Developer options (tap Build number seven times in About phone), then turn on Pointer location. Your finger now draws a line.
2. Drag slowly across the whole screen, along every edge and into the corners. A gap in the line is a dead zone.
3. Put the phone down and watch for 30 seconds. Lines appearing by themselves are ghost touches.
4. Touch with two and three fingers at once.

Display: dead pixels, lines and burn-in

1. Show full-screen white, black, red, green and blue pages at full brightness.
2. On black, look for bright dots; on white, for dark dots and yellow or pink areas near the edges.
3. On grey, look for the ghost of the keyboard or status bar: that is OLED burn-in.

Questions

How do I test every part of a touch screen?

Drag one finger slowly over the whole screen, including the edges and corners, and watch whether the touch follows without gaps. Android's Developer options include Pointer location, which draws your touch. Knowfone guides your finger over every 7 mm of the glass and maps the parts that do not respond.

What is a ghost touch?

A touch the phone registers when nobody is touching it. It makes apps open by themselves and often comes from a damaged or cheap replacement screen.

How do I check for burn-in?

Show a full-screen grey page at full brightness. On OLED screens, burn-in shows as faint shapes of the keyboard, status bar or navigation buttons.

Is there a hidden test menu?

Many Samsung phones open a hardware test menu when you dial *#0*# in the phone app. It does not work on every brand; see the test codes for each brand.

Run them now in your browser: touch screen test, dead pixel test and multi-touch test.