When the flashlight on your OnePlus Nord 4 won't turn on, it's a surprisingly frustrating hiccup. You might tap the quick settings tile and nothing happens, or the icon just seems unresponsive. Let's get that light working again.
Force Close the Camera App
The flashlight and camera flash on your Nord 4 use the same physical LED. If the Camera app is running, even in the background, it locks control of that light. Swipe up from the bottom and hold to enter the recent apps view, then swipe the Camera app away to close it. You should be able to use the flashlight immediately after.
Perform a Force Restart
This is the go-to fix for most minor glitches. Simply press and hold the Power button on the right side of your Nord 4 for about 10 seconds. Keep holding until you see the OnePlus logo appear, then release. This reboots the system and clears any temporary software state that's blocking the flashlight function.
Check Your Quick Settings Tile
Swipe down from the top of the screen twice to open the full quick settings panel. Find the flashlight tile, it looks like a torch. If it's not there, you may have removed it. Tap the pencil icon to edit your tiles and drag the flashlight icon back into your active set.
Let Your Phone Cool Down
The Nord 4's metal unibody is great for heat dissipation, but intensive use can still cause overheating. As a protective measure, OxygenOS will disable certain features, including the flashlight, if the phone gets too hot. If the back feels warm, stop using it for a bit and let it cool down in a shaded spot for 10-15 minutes.
Use Google Assistant as a Workaround
Say "Hey Google, turn on the flashlight" or press and hold the power button to activate Assistant and give the same command. If Assistant can turn the light on but the quick settings tile still fails, it points to a minor interface bug. A simple restart, as mentioned earlier, should sync everything back up.
Adjust the Flashlight Brightness
You might not realize the light is on if it's set to its dimmest level. Press and hold the flashlight tile in your quick settings panel. A small pop-up menu should appear with a brightness slider. Slide it all the way to the right to the brightest setting and try turning the flashlight on again.
Update OxygenOS
Go to Settings > About device > OxygenOS version and tap on the top banner to check for updates. OnePlus regularly releases software updates that squash bugs, including ones that affect system features like the flashlight. Installing the latest available update is a solid step.
Reset App Preferences
This resets permissions and default actions for all your apps without deleting any personal data. Navigate to Settings > Apps > See all apps > Menu (three dots) > Reset app preferences. Confirm the reset. This can resolve conflicts where a system app's settings have become corrupted.
Test the Camera Flash
Open your Camera app and switch to a photo mode. Try taking a picture in a dark room or look for a flash icon to turn it on manually. If the camera's flash also doesn't fire, the issue is likely with the LED hardware itself. Since the Nord 4 has a sealed metal body, you'd need to contact OnePlus support or a professional repair service for a diagnosis.
