The touch screen on your Android smartphone can sustain damage from drops, scratches, pressure and moisture. If you suspect that your touch screen is not working properly, there are several applications in the Google Play store that can help you test its functionality, so that you can repair or replace it if it is indeed damaged.

Symptoms of Damage

Symptoms of a damaged Android touch screen can present in many ways. If the liquid crystal display, or LCD, has been damaged, you may notice smudging or blackened areas that resemble ink. Damage this severe most likely requires replacement of the display. A damaged touch screen may not respond to touch at all, or respond unpredictably or even make selections on its own. If you've dropped the phone, look for cracks, scratches or spidering in the glass. Depending on the amount of physical damage, it may be possible to replace the glass without having to replace the LCD underneath.

Screen Testing Apps

Screen Touch Test, Multitouch Test and Simple Touchscreen Tester are free apps, available on the Google Play store, that test how well your touch screen registers input from your fingers (links in Resources). These screen testing apps can also be helpful in diagnosing touch screen problems such as dead spots, and determining the accuracy of the display.

Testing Your Android's Display

Before using a screen testing app on your Android's touch screen, clean the display thoroughly using a soft cloth to remove fingerprints, dirt and debris. Open the screen testing app, and then test the screen by touching, swiping and tapping on the display. The app then shows you what areas of the screen are registering your touch and how accurate it is. An app that supports multitouch, like Multitouch Test, can also tell you how many simultaneous finger touches your Android device supports at one time.

Considerations

Screen testing apps only test to a certain level of accuracy. This can depend on the pixel density of your Android touch screen, which varies from device to device. This means that you shouldn't rely on just a single app to diagnose a touch screen problem. Test your display using multiple apps and compare the results to one another. If you notice a consistent problem with registering your touch, bring the phone to a repair specialist who can tell you whether the display can be repaired or if it needs to be replaced altogether.