Can't read SIM cards after the latest update

[ErikViking]

Hello,

I received and installed a firmware update two days ago. I noticed cell signal icon was replaced by a crossed circle; 🚫. Also, the options for 4G and 5G are nonresponsive, the menu options are not greyed out but they are unresponsive when pressed. So I can't connect to my cell service provider. Tried lurking around the web for a day with no success.

What I've tried:

-Restart

-Flight mode on/off

-Reinstall sim card in both slot 1 & 2 - !There's not even any prompt for entering SIM-card! The phone doesn't even seem to be looking for a SIM-card.

-Confirmed SIM to be working on another phone

-Factory reset

Hardware: SM-G9810, Snapdragon Korea version 5G

Firmware: One UI 3.1, security patch September 1, G9810ZHS3DUI1 / G9810OZS3DUI1 / G9810ZCS3DUI1

Right now I'm torn between trying to downgrade or await the next update hoping it magically solves the problem.

I would be glad to know if you've heard about any similar cases and welcome any creative attempt of solving the issue!

[Rūmøur]

@ErikViking Any update on the situation yet??

[ErikViking]

Yes, I just talked to the service team. There's not enough users affected by this error in order to motivate them to work on a fix, what they suggested were to hand in the phone to Samsung and get it replaced. Not happy with the response since I have a Snapdragon, they'll most likely try to replace it with an Exynos which obviously isn't the same thing. I'll update on how smooth the phone replacement/compensation goes. 

[Rūmøur]

That's such a BS response. Cant believe samsung are actually saying this. Do you think your phone is going to be replaced here in the UK since its a non EU model?

[ErikViking]

I know right, I think their initial response was an attempt to make me feel content. I've been in further contact with my local Samsung repair shop. They wont accept my phone. Apparently warranty is strictly region bound and only an Asian repair shop are able to work on my phone.

Given the issue is purely software, which I heavily suspect - there are two paths going forward. First, patiently wait for One UI 4 beta to drop. Potentially it could make everything work all of a sudden, in the same way last update made everything not work all of a sudden... If that won't fix it, the last option is root and flash some custom ROM, either LOS/AOSP or maybe change region code on the phone in order to flash an EU ROM (sine hardware wise, the Korea model supports the GSM bands utilized within EU).

A curve ball would be the scenario where some circuit regarding SIM & baseband got fried during the latest firmware upgrade. That would mark end of life for this phone.

[Rūmøur]

Yes that's what I've decided to do as well. Waiting for the one ui 4 beta. My phone is the s21 ultra hong kong version. If oneui 4 beta does fix this I'm shipping it back to have it fixed or replaced since I'm still within my warranty period. I also suspect it's a software issue. Sent it for repairs when this happened and they couldn't find any problem with the hardware..did a software downgrade and that didnt also fix the issue. Running a sim and network diagnostic test on samsung members also states everything is normal so I'm definitely suspecting a software issue. I've used Samsung devices for years and this is the first time I'm ever facing such an issue. Been hanging on since august. Mine started after i did the July security update.

[ErikViking]

Oh wow, that really sucks. July! I'm shocked the software downgrade didn't fix the problem. Either some drivers or module separate from the core ROM got overwritten with new instructions, which later on doesn't get overwritten by downgrading to an older OS, since the module have already have later instruction sets with later revision numbers. In that case the phone would need to be fully wiped on all levels, not just OS. Then get a fresh set of matching software, preferably the latest confirmed functioning OS.

The pattern does honestly feed the theory of some obscure hardware defect (so obscure that Samsung's diagnostic tools aren't programmed to even look for this odd issue).

I can't think of any other possible scenario.

I have been in quite a lot of software development with Android and I work with wireless network communication. I have never encountered this odd of a behavior, not with any Samsung or any other manufacturers. And I've gone through A LOT of devices. 

[Rūmøur]

This is all quite a mess. Really hoping OneUi 4 beta somehow manages to fix this. This has happened to Samsung phones in the past before. It happened to the Note 8. The exact same situation. Only this time, a lot more users faced this problem. In under two days samsung released a patch fixing this. So I'm really certain this is a software related issue looking at past incidents

[Neiladue]

Worked for me after October 1st update. Thanks

[Rūmøur]

Any update?

[ErikViking]

Still not working.. placing all my hopes in one UI 4, unfortunately there's no beta files in circulation for SM-G9810.

Also, Samsung service still refuses to touch or help me with my device.