Original topic:

S21 randomly shutting off after dropping cell signal

(Topic created: 08-25-2021 10:42 PM)
LordKitsune3
Asteroid
Options
Galaxy S21

This is going to include quite a lot of information and will end up being a text wall. Read this all the way through before replying, as most of the things that will be suggested to me have already been considered, done, or are not available to me.

 

I bought my S21 ULTRA (Unlocked) on 03/26/2021. I was using it on Verizon for several months with no issues outside of Verizon's awful coverage in my area. Last week (08/18/2021) the phone started to randomly shut itself off after dropping cell signal. I have the same exact thing happening with my AT&T sim as well, even though I have much better signal strength. From what I could tell I was not having overheating issues (I have see that floating around as a major issue of the entire S21 lineup), with my highest core temps being around 60C (should not be an issue for modern silicon to operate at that temperature), battery never exceeding 30 or 40C.

 

I started digging around trying to find solutions on my own, here is what I tried:

Airplane mode on then off

Reset Network Settings (Probably done this about 100 times now)

Clear Cache (Via the bootloader menu - where you power down the device then power it on while holding the volume up button w/power)

Reseating the Sim 

Cleaning Sim card and Sim Tray/Slot (I have an anti-static blower made for cleaning electronics)

Factory Reset (Both in the settings menu and in the bootloader menu)

Nothing had worked, so I finally broke down and made the drive to my nearest authorized Samsung repair center (about an hour away). They "factory reset" the device (at a deeper level than what the user can do through software). That seemed to have fixed the issue. My drive up there had the device losing service multiple times and restart once, had almost perfect signal the whole way back. This was 2 days ago (8/23/2021).

Yesterday the device restarted itself unprompted and started dropping signal again. This was all while being virtually right beside a cell tower for my carrier, so signal strength would not be the cause.

Today I have been pretty much unable to use the device without being on wifi.

I have no issues with wifi connectivity. At all. When cellular works, I get expected speeds for my area.

I will note that I am not on the most current software for the device. I will be updating after I post this to see if Samsung issued a software patch for this issue (I am currently operating under the belief this is some software issue and not hardware).

I haven't had any sort of overheating problems with the phone. I've seen plenty of stuff floating around about that and I haven't seen it on my device.

I was wondering if anybody else is having this issue, and if so how many people might be affected...

Kinda defeats the purpose of a phone if it can't keep cellular connectivity!

7 Replies
StimmyPizza
Nebula
Options
Galaxy S21
Im not sure what the exact cause is for that but Update it and check to make your security Update and Google Play system Update are both on the latest version too, and run galaxy app booster in Good Guardians after your updates.

This is just a thought too, but maybe try running an anti virus, that type of behavior can be due to a virus (although fairly rare but doesn't hurt to do it)

If anything you're still under warranty and should be able to claim that.
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SamsungAdam
Samsung Moderator
Samsung Moderator
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Galaxy S21

Thank you for reaching out. I can certainly understand how frustrating this can be and would be happy to assist you further. The next thing I would try is your device in safe mode. If your phone is misbehaving, it's possible that a third-party app is causing the issue. To figure out what app is acting funny, you can use the Safe Mode feature. In Safe Mode, your phone won't run any third-party apps. This allows you to easily identify and remove the app that may be causing the problem. Give this link a try: https://www.samsung.com/us/support/answer/ANS00062983/


Be sure to click " ✓ Accept as Solution" when you find an answer that works for you.





Please note, notification emails are a DO NOT REPLY address, you must log-in on the community page in order to respond.

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LordKitsune3
Asteroid
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Galaxy S21

Safe mode did nothing for the issue - it was one of the steps I tried prior to taking the device to a Certified Repair Center (the step I had forgotten to write down as well). I tried uninstalling everything manually and through factory reset(s) and was still having the same issue.

The only thing that had any effect was running the phone in "Power Saving Mode" 24/7 and that still had the phone doing the same thing. Also defeats the purpose of having a flagship if I have to run it at 70% SoC capabilities. 

Regardless, my phone is on its way to Samsung now. Hoping they can figure out the issue. 

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Krogersupervisor1
Astronaut
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Galaxy S21
I would recommend that you get a cellphone booster an put out in your home to help with the network to get a better signal in case they are doing some repairs on the Cellphone tower Near you.
LordKitsune3
Asteroid
Options
Galaxy S21

A good 2 years ahead of you on that and yes, it does support some of the bands on the towers in my area. Like I said in my original post, it was happening regardless of cell signal strength. I could have signal < -90dbm and it would start saying no SIM or Network not Found.

On that note - I bought a backup phone and am using the EXACT same SIM so that verifies that it wasn't a SIM issue.

Krogersupervisor1
Astronaut
Options
Galaxy S21
That is absolutely odd. Next it happens. Take a screen recording and then call Samsung an day I want to show a screen recording of what's happening and let them see it thru screen sharing an if they say there is nothing that can be done on there end! Go back to your service provider were you have service with and show them the exact same video an see what they recommend an say, if possible, I would like to get a tech out an have them do some testing in my area.
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clarabell
Astronaut
Options
Galaxy S21
I have to tell you it isn't your connectivity or signal strength...in my opinion. I have had a similar issue. I purchased a s21 as a pre-order in January. I had issues with shutdown randomly and repeatedly all day long sometimes 13 times before 10 am. Samsung forced me to drive 2 hours one way to a youbreak I fix store. They said it was s known issue and the first ones were effected. They ordered me a new one. 2 hours back hone ...2 hours back to pick it up ..2 hours home. Only two days later... issue starts again. No help from samsu g .I can either send it in" or go back 2 hours to that store. I went back They preferred me a new one was suppose to çome in 3 to 4 days ..3 weeks no phone yet. No answer from samsung. Check into your issue and good luck
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