Touch screen not working: how to find the cause

First, map what still works

Open the touch screen test and draw slowly across the whole screen, row by row, including the corners and the edges. Every point the screen reports leaves a mark, so gaps show up as blank stripes or patches. Then put several fingers down at once to check multi-touch.

• Nothing registers anywhere: start with the basic checks below; if none helps, it is likely a system or hardware fault.
• A stripe or patch stays blank: a dead zone. Note where it is, then follow the checks.
• Marks appear where you did not touch: ghost touches. See the section below.
• Everything registers in the test but not in one app: the screen works; that app is the problem.

Basic checks for every device

1. Clean the screen with a soft, dry, lint-free cloth. Water drops, grease and dirt can cause missed touches and false touches.
2. Remove the case and screen protector, and test again. A tight case pressing on the edges, or a protector with bubbles or lifted edges, is one of the most common causes. Both Apple and Google list this step.
3. Dry hands, no gloves: wet, very dry or gloved fingers register badly on capacitive screens.
4. Unplug accessories and chargers: Apple recommends disconnecting Lightning or USB-C accessories; a faulty charger or cable can make touch erratic while connected.
5. Restart the device. If the screen is too unresponsive to use the menus, use the force-restart method for your model.

iPhone and iPad

Apple's guidance for a screen that is unresponsive or responds intermittently is: restart, make sure the screen is clean and free of debris or water, disconnect accessories, and remove cases or screen protectors. If the screen still does not work, Apple recommends setting up service.

If touches register but feel wrong (too sensitive, needing a long press, accidental taps), check the Touch settings in Accessibility, where touch accommodations can change how the screen responds. Those settings change behaviour; they do not repair a faulty screen.

Android phones and tablets

Google's Android troubleshooting follows a similar order:

1. Check the screen for cracks or chips, remove any case, protector or stickers, and clean it.
2. Force restart by holding the power button for about 30 seconds, or until the phone restarts.
3. Start in safe mode and test the screen. If it works in safe mode, a downloaded app is the likely cause: leave safe mode and uninstall recent apps one at a time.
4. Turn off developer options if you have enabled them.
5. As a last step, a factory reset, which erases all data, so back up first. If the problem continues, contact the manufacturer or carrier.

Some phones, including Pixel models, have a screen protector mode or touch sensitivity setting in the display settings. Turning it on can help with a thick protector.

Windows laptops and touch monitors

• The touch screen may be disabled: Microsoft explains how to turn it back on in Device Manager: expand Human Interface Devices, right-click HID-compliant touch screen and choose Enable device. If there are several entries, do it for each.
• Touches land in the wrong place: Windows has a calibration tool. Search Start for Calibrate the screen for pen or touch input (part of Tablet PC Settings in Control Panel) and choose Calibrate. On a setup with several monitors, use Setup there so Windows knows which screen is the touch screen. Do not confuse it with display colour calibration.
• External touch monitors usually need a USB cable for touch in addition to the video cable.
• Run Windows Update, and check the laptop manufacturer's support page for your model if touch disappeared after an update.

Ghost touches and dead zones

Ghost touches are taps or swipes you did not make. Common causes are moisture or dirt, a protector or case pressing on the edge, a faulty charger, and a screen under pressure from a bent frame or a swollen battery. Test with nothing connected, no case and a clean, dry screen. If ghost touches continue, and especially if the screen or back of the device is lifting, stop charging it and have it checked.

A dead zone that stays in the same place after cleaning, without a protector and after a restart, usually means damage to the digitizer, the touch layer of the screen. That needs a repair or a replacement screen, not a setting. The touch screen test is useful to show the exact area to a repair service, and to check the result after a repair.

Buying a used phone or tablet? Add the touch test to the checks in how to test a new monitor and run the dead pixel test too.