Phone Screen Goes Black During Calls? Causes and Fixes

Short answer

During a normal call the screen is supposed to go black and ignore touches while the phone is against your face. That is the proximity sensor doing its job. The problem starts when the screen stays black after you move the phone away, never wakes up mid-call, or flickers on and off. Four things cause most cases: a case or screen protector over the sensor, dirt or oil on it, a bug in the phone app, or a failing sensor. Check them in that order, because the first three cost nothing.

To see what your sensor is doing, open our proximity sensor test. Many mobile browsers don’t let a web page read this sensor, so the page also walks you through a hands-on test you can do in ten seconds.

Is it normal or a fault?

• Black while the phone is at your ear, back on when you pull it away. Normal. Nothing to fix.
• Stays black after you take the phone off your ear. A fault. The sensor still thinks something is close. This is the main problem this guide fixes.
• Black on speakerphone. A fault. On an iPhone the screen may dim on speaker but should not go fully black, according to replies from other users in Apple’s support community.
• Flickers on and off against your ear. Usually dirt or a partly covered sensor. Dust inside the phone can cause this after a screen replacement.
• The opposite: the screen stays on and your cheek hangs up or mutes. Same sensor, different symptom. Our ghost touch guide covers touches the screen invents on its own, which is a separate fault.

Step 1: Test the sensor

1. Open the proximity sensor test on the phone.
2. Find the sensor. It sits at the top of the front, next to the earpiece slot and the selfie camera. The page has a diagram.
3. Cover that spot with your finger, then lift the finger away. A working sensor reports “near” when covered and “clear” when uncovered. On phones where the browser can’t read the sensor, use the page’s manual test: during a real call, cover the top of the screen and see if it goes dark.
4. If it says “near” with nothing covering it, the sensor is blocked or stuck. If it never says “near”, the screen will stay lit during calls instead.

Some Android phones also have a built-in hardware test in a service menu. The code differs by brand, so look up your exact model before you dial one, and don’t change settings you don’t understand there.

Step 2: Remove the case and check the screen protector

A case lip, a thick tempered-glass protector, a cheap film or a privacy filter can sit over the sensor. Guiding Tech lists this as the first thing to check, and ASUS says to replace a screen protector that blocks the sensor. Take the case off and make a test call. If the problem goes away, the case is the cause. If a protector is the cause, fit one with a proper cut-out or one made for your exact model, because the sensor position varies by phone.

Step 3: Clean the sensor area

Wipe the top of the screen around the earpiece and camera with a dry, soft microfiber cloth. Oil from your face and skin builds up exactly where the phone touches your cheek. In Apple’s support community, one person said wiping that area with a dry cloth cleared the problem twice. Don’t spray liquid onto the glass or push anything into the earpiece slot.

Dust inside the phone is a different case. One Fairphone owner traced a flickering black screen to dust and residue around the sensor behind a replaced display. That needs a repair shop, because the phone has to be opened.

Step 4: Restart and update

1. Restart the phone. On an iPhone that stays black, a force restart works even when the screen won’t respond. A restart cleared the problem only temporarily for some people, which points to a sensor fault if it returns.
2. Install updates. Update the system and the phone app. ASUS lists outdated firmware and an outdated contacts app as causes, and Guiding Tech suggests an update for Samsung phones.

Step 5: Fix the phone app (Android)

• Use the default dialer. Guiding Tech notes that a bug in a third-party phone app can cause the black screen. Go to Settings → Apps → Default apps → Phone and pick the built-in one, then call again.
• Reset the app. Press and hold the Phone icon, tap App info, then Force stop and Clear cache. If that doesn’t help, the same menu may offer Uninstall updates for a system dialer. Menu names vary by brand.
• Turn the feature off as a workaround. ASUS says you can switch off the proximity sensor option in the call settings, so the screen stays on during calls. Other brands may not offer it. Your cheek may then press buttons, so treat this as a stopgap.

If the screen is black right now, mid-call

• Press the side or power button once. Guiding Tech lists this as a way to turn the display back on during a call.
• Hold the phone away from your face, then cover and uncover the top of the screen to re-trigger the sensor.
• On Android, you can turn on the accessibility option that lets the power button end calls, so you can hang up without the screen.
• If nothing works, force restart. The call will drop.

Step 6: Reset settings as a last software step

If the problem began after a software change, reset settings without erasing data. On iPhone: Settings → General → Transfer or Reset iPhone → Reset → Reset All Settings. On Android, look under Settings → System (or General management) → Reset options. This clears Wi-Fi passwords, Bluetooth pairings and permissions but keeps photos and apps. A full factory reset is a bigger step. Back up first, and use it only if a repair shop or the maker asks.

What your results mean

• Fixed after removing the case or cleaning: it was blocked. Nothing is broken.
• Fixed after switching dialer or clearing the app: a software bug in the app.
• Comes back after a restart: the sensor or its connection is probably faulty.
• Sensor reports “near” with nothing over it, or never reports it: a hardware fault, or a replaced screen that was fitted badly.

When to repair or replace

If a clean, case-free phone still fails after a restart, an update and a settings reset, the sensor needs service. If you had the screen replaced recently, go back to that shop first: a sensor that stopped working after a repair is often a part that wasn’t seated properly. For a phone under warranty, carrier protection or AppleCare, contact the maker or carrier before a third-party shop. Apple community advice is to book a store appointment and note when it happens, because staff may need to see it. Get a written quote and compare it with the phone’s value using our phone value estimator. On an older phone with a worn battery or other faults, replacing the handset may cost less than repairing it.

In the UK, Canada and Australia the same steps apply. Only the warranty and consumer-rights rules differ, so contact the retailer first for a faulty newer phone.

Buying a used phone?

Test the sensor in person. Make a short call, hold the phone to your ear, then pull it away and check the screen wakes. Run the full phone test too, and read our guide on earpiece and speaker faults, since the sensor sits beside the earpiece. If the screen has been replaced, a badly fitted sensor is a common leftover. The used iPhone checklist covers the rest.