Proximity, auto-rotate or face unlock not working? How to test your phone's sensors

Match the symptom to the sensor — it's the fastest way to diagnose:

Our free sensor test checks the motion and orientation sensors so you can confirm whether they're responding at all. For the proximity sensor, make a call and cover the top of the screen — it should switch the display off; for auto-rotate, enable rotation and turn the phone sideways.

A lot of sensor issues are software or accessory problems, not failed hardware:

• Restart the phone to reset stuck sensor services
• Install pending updates (sensor bugs are often patched)
• Remove a screen protector covering the proximity or face-unlock sensors at the top
• Take off a case that overlaps sensor cut-outs
• Re-enroll your face for face unlock; recalibrate the compass by moving the phone in a figure-8

If the screen stays lit during calls and your ear keeps muting or hanging up, the proximity sensor isn't reading correctly. After ruling out a screen protector or case over the top of the screen, the usual hardware cause is a previous screen replacement with a cheap panel, or damage after a drop.

Suspect hardware if a sensor failed right after a screen replacement, a drop, or water exposure, or if software fixes do nothing. Sensors are usually part of a flex cable or the front assembly, so the fix is a component replacement. iTweak diagnoses which sensor and shows you before quoting, for Apple and Android, with warranty and a digital invoice.