Technician helping troubleshoot OnePlus alarm not going off

Steve H.

Reviewed for technical accuracy

Specialities: OnePlus alarm and notification issues (alarm not ringing, silent alarms, Do Not Disturb conflicts), battery optimization and background app restrictions, Android update settings after system upgrades

OnePlus alarm not ringing, silent alarms, alarm volume muted — safe checks (Do Not Disturb, battery optimization, volume settings, notification permissions) before you change anything

Technician avatar Technician
I hear you. When your OnePlus alarm stops going off, especially after an update, it can feel like the phone has a mind of its own.

Trust moment: let’s not reset the whole phone or delete apps just yet. We’ll check the safest settings first, and you can stop at any point.

Quick start: did the alarm stop working right after a system update, or did it happen gradually? And does the alarm app show the alarm as set (turned on), or does it appear disabled?
Customer
It happened right after the update last week. The alarm shows as on in the app, but it doesn’t ring. My phone is on. I’ve tried setting it multiple times.
Technician avatar Technician
That timing is important. After an update, Android sometimes changes how apps handle notifications and sound. The alarm app might be blocked from making noise even though it’s set.

Before we dig deeper: when the alarm time arrives, does the screen light up or vibrate at all, or is it completely silent and dark?
Customer
It’s completely silent and dark. Nothing. It’s like the alarm never fires. I don’t see any notification either.
Technician avatar Technician
That’s a clean clue. If there’s no vibration or notification at all, the alarm app itself might not be triggering. This usually points to one of three things after an update:
• Do Not Disturb (DND) is on and blocking alarms.
• Battery optimization is preventing the alarm app from running in the background.
• The alarm app lost notification permissions after the update.

Let’s start with the easiest: is your phone in Do Not Disturb or Quiet mode? You can usually see this as an icon at the top of the screen or in Settings.
Customer
I checked and Do Not Disturb is off. But I’m not sure about battery optimization. The phone is plugged in usually, so I didn’t think about that.
Technician avatar Technician
Good instinct. Battery optimization is often the culprit after updates. Even if your phone is plugged in, OnePlus (and Android in general) can still restrict apps from running in the background if they’re marked as “optimized” or “restricted.”

Trust moment: I don’t want you changing deep system settings or disabling security features. We’ll just check if the Clock app (which runs your alarms) is on a restricted list.

Can you go to Settings > Battery > Battery optimization (or similar) and see if you can find the Clock or Alarm app listed there?
Customer
I found it. It says “Clock” is in the optimized apps list. There’s a button that says “Remove from optimization” or something like that.
Technician avatar Technician
That’s very likely the reason. When the Clock app is optimized, the system can suspend it when the phone is asleep, which means the alarm never triggers. Removing it from optimization should let the alarm run normally.

Tap that button and allow the Clock app to run in the background. After that, test the alarm by setting one for a few minutes from now and see if it fires.
Customer
Done. I removed it from optimization. Now I set an alarm for 5 minutes from now. It went off! The phone vibrated and made a sound. I’m so relieved.
Technician avatar Technician
Excellent. That’s the fix. The update must have reset the Clock app’s battery optimization setting, which is a known issue on OnePlus after major updates.

One follow-up to make sure it stays fixed: check if there are any other alarm-related apps you use (like a third-party alarm app), and if so, remove them from optimization too. Also, if you see a notification permission prompt for the Clock app, make sure to allow it.
Customer
I only use the built-in Clock app. No third-party alarms. And I allowed notifications when it asked. Thank you so much. I was worried something was seriously wrong.
Technician avatar Technician
Not at all. This is a very common side effect of system updates on OnePlus. The good news is it’s reversible and doesn’t require a factory reset or any risky changes. Just a simple setting adjustment.

Going forward, if you notice other apps aren’t working as expected after an update, battery optimization is often the first place to check. And if the alarm ever stops working again, you know exactly what to look for.

Quick answer: the accepted fix

Accepted first fix for OnePlus alarm not going off (safe approach): 1) confirm Do Not Disturb is off and the alarm app has notification permissions enabled, 2) go to Settings > Battery > Battery optimization and check if the Clock app is listed in optimized/restricted apps, 3) if it is, tap Remove from optimization (or “Unrestrict”) to allow the Clock app to run in the background, and 4) test the alarm by setting one for a few minutes ahead to confirm it fires with sound and vibration. This is especially common after a system update, when the optimization setting may reset unexpectedly.

Why OnePlus alarms stop working after an update (and why battery optimization is usually the cause)

When a OnePlus alarm stops ringing right after a system update, it’s rarely a hardware failure. Instead, the update often resets or changes how the operating system manages background apps. OnePlus uses aggressive battery optimization to extend battery life, and after an update, the Clock app (which handles alarms) can be moved back into the “optimized” list. This tells the system to suspend the app when the phone is asleep, preventing the alarm from triggering. The alarm shows as “set” in the app because the reminder is stored locally, but the system never wakes up the Clock app to actually ring it. The fix is simple: remove the Clock app from battery optimization so it can run in the background and trigger alarms normally.

What to check first (safe checks before changing anything advanced)

Start with the least risky step: confirm that Do Not Disturb is off and that the alarm app has notification permissions. Next, check if the Clock app is in your phone’s battery optimization list by going to Settings > Battery > Battery optimization (the exact menu name varies by OnePlus model and Android version, but it’s usually under Battery or Device Care). If the Clock app is there, removing it from optimization is the key fix. You can also test the alarm by setting one for a few minutes ahead instead of waiting for tomorrow morning. If the test alarm works, you know the issue is resolved. For more OnePlus troubleshooting topics, see Troubleshooting Guides and Mobile Troubleshooting.

OnePlus alarm troubleshooting — calm, senior-friendly guidance

Focus on the settings that actually control whether your alarm can ring: battery optimization, Do Not Disturb, and notification permissions.

If your OnePlus alarm is not going off, don’t panic or assume the phone is broken. After a system update, the most common reason is that the Clock app got moved into battery optimization, which prevents it from running when the phone is asleep. The alarm still appears “set” in the app because the reminder is there, but the system never wakes up to trigger it. Removing the Clock app from battery optimization is usually all you need. You can test this immediately by setting an alarm for a few minutes from now. If it rings, the problem is solved. Do Not Disturb and notification permissions are also worth checking, but battery optimization is the most frequent culprit after updates.

Disclaimer: This information is AI-generated and intended for general guidance only. Avoid changing deep system settings or factory resetting unless you are sure. For model-specific menus and screens, use official OnePlus documentation or contact OnePlus support.

If the issue continues

Getting Started Is Easy

Ask for help, 24/7

If your OnePlus alarm is silent, start with the safest checks: Do Not Disturb off, notification permissions on, and the Clock app removed from battery optimization. No deep settings needed.

Expert will respond in minutes

Most alarm failures after a OnePlus update come down to battery optimization resetting the Clock app. A quick check and one setting change usually fixes it completely.

Stop missing alarms

Once the Clock app is removed from battery optimization and has notification permissions, your OnePlus alarm will ring reliably every morning without any extra steps.

FAQ

Why did my OnePlus alarm stop working right after a system update?

System updates sometimes reset app settings, including battery optimization. If the Clock app gets moved into the “optimized” or “restricted” list, the system suspends it when your phone is asleep, so the alarm never triggers. The alarm still shows as “set” in the app, but the system doesn’t wake up to ring it. Removing the Clock app from battery optimization fixes this.

What is battery optimization and why does it affect alarms?

Battery optimization is a feature that restricts how much power background apps can use to extend battery life. However, when an app like Clock is optimized, the system can suspend it entirely when the phone is asleep. Since alarms need to trigger even when you’re sleeping, the Clock app must be allowed to run in the background. Removing it from optimization lets it work normally.

My alarm still doesn’t work after removing it from battery optimization. What else could it be?

Check a few other things: make sure Do Not Disturb is off (it can block alarms even if the app is running), confirm the Clock app has notification permissions in Settings, and test with an alarm set for a few minutes ahead instead of tomorrow morning. If a test alarm works, the issue is likely a one-time glitch. If nothing works, contact OnePlus support or try clearing the Clock app’s cache (Settings > Apps > Clock > Storage > Clear Cache).

Is it safe to remove the Clock app from battery optimization?

Yes, it’s completely safe. Removing an app from optimization just means the system won’t suspend it when your phone is asleep. It may use slightly more battery, but alarms are essential and should always be able to ring. You can always put it back into optimization later if you notice battery drain, but most users don’t see a significant difference.

Sources

Filed under: Sensors & Permissions

Matt Verified Icon
Matt ● replies in < 1 min
Technician Expert
⭐⭐⭐⭐⭐ Trusted by 27,000+ customers
Avatar
Alex · Expert's Assistant
5 Tech Support Specialists are online right now.