topic Re: Samsung Note Ultra 20 5G Restarting Issues in Galaxy Note Series

Samsung Note Ultra 20 5G Restarting Issues

Rachelle — Tue, 31 Aug 2021 22:40:34 GMT

My phone is restarting by itself multiple times throughout the day. I made no changes to settings. Just started doing that today. I use my phone for work so when it restarts randomly I lose everything I was just doing. Anyone experience this and know how to resolve it.

Re: Samsung Note Ultra 20 5G Restarting Issues

antikythera — Tue, 31 Aug 2021 23:35:22 GMT

that's a sign that either Android or a critical component of it is crashing repeatedly. Take a look in device care for any reports of crashing apps and uninstall any culprit if you can. make sure that all app and system updates have been applied to avoid crashes and instability.

clearing cache is the 2nd option. the 3rd and most drastic is a factory reset but you will lose anything you have not backed up to PC, cloud or external media if you do that. should none of these work you need a potential hardware issue repaired.

Re: Samsung Note Ultra 20 5G Restarting Issues

leicesterMan — Wed, 01 Sep 2021 00:37:18 GMT

Also check which app was last installed, happened to me, and I deleted an app, and it was back to normal

Re: Samsung Note Ultra 20 5G Restarting Issues

Rachelle — Tue, 07 Sep 2021 23:38:46 GMT

It ended up being The Ring app. After uninstall my phone stopped restarting by itself. So weird. Thank you!

Re: Samsung Note Ultra 20 5G Restarting Issues

Rachelle — Tue, 07 Sep 2021 23:40:46 GMT

It ended up being The Ring app. Once I uninstalled that app my phone was back to normal. So weird. Thank you!

Re: Samsung Note Ultra 20 5G Restarting Issues

ewadim — Fri, 09 Jan 2026 19:08:16 GMT

For a Samsung Galaxy Note 20 Ultra, a sudden restart issue occurring in 2026 most likely indicates either hardware degradation (the battery or motherboard has around 5–6 years of use) or a major software conflict.

Here are the specific steps for your model to try fixing the issue without losing your data:

1. Disable “Auto Optimization” (Auto Restart)

The Note 20 Ultra has a feature that automatically restarts the phone for “system health.”

Go to Settings > Device Care.
Tap the three dots in the upper-right corner or search for Auto optimization.
Ensure that the options Restart when needed or Restart on schedule are disabled.

2. Clear the Cache Memory (Wipe Cache Partition)

This operation deletes temporary system files that might cause errors, without deleting your personal data.

Power off the phone completely.
Connect it to a computer or USB-C headphones (on the Note 20 Ultra this step is often required to access the recovery menu).
Press and hold Volume Up and Power simultaneously until the Samsung logo appears.
Use the volume buttons to navigate to Wipe Cache Partition and press Power to confirm.
After completion, select Reboot system now.

3. Check the Battery (Diagnostics)

If the phone restarts when the battery drops below 40–50% or under heavy use (e.g., opening the camera), the battery is most likely the cause.

Open the Samsung Members app (preinstalled).
Go to Support > Phone diagnostics.
Run the test for Battery status. If it shows “Weak” or “Action required,” the battery needs replacement.

4. Use Safe Mode for Work

If you urgently need to use your phone for work and want to avoid restarts caused by apps like Facebook, WhatsApp, or optimization apps:

Press and hold the Power button, then press and hold Power off on the screen until Safe Mode appears.
In this mode, only factory-installed apps will run. If the phone no longer restarts, a recently installed app is responsible.

5. Signs of Motherboard Failure

If the phone overheats before restarting or the screen “freezes” even after a reset, the motherboard may have developed micro-cracks (an issue reported by some Note 20 Ultra users after several years). In this case, the only solution is an authorized service center.

Urgent Recommendation:
Enable Auto-save in Microsoft Office or Google Docs, and make a full backup to Samsung Cloud or Google Drive as soon as the phone is stable, to avoid losing work data.