Just wanted to reach out and see what everyone's thoughts/recommendations are.
Device:
Samsung Galaxy S23 Ultra (512GB, Factory Unlocked, purchased from Amazon โ official seller)
~2.5 years old
Never opened or repaired
After updating my S23 Ultra to the February/March 2026 security update overnight, I woke up and noticed I was no longer getting cellular service (showing โEmergency calls onlyโ), and the fingerprint sensor was malfunctioning, giving a message along the lines of โSensor not available, not working properly, please try again later" when trying to sign into apps using my fingerprint.
I contacted T-Mobile, and they confirmed the lack of service was not on their end. They checked for outages and issued a new eSIM, which did not resolve the issue.
As for the fingerprint scanner, I removed all saved prints and tried setting them up again. After about 80% completion, it fails with the same sensor error message. I also ran diagnostics through the Samsung Members app and the *#0*# menu, and both reported that the fingerprint sensor is functioning normally.
Later in the day, while scrolling, the phone suddenly froze and auto-restarted. It wasnโt overheating, so I didnโt think much of it. However, after turning back on automatically, it continued to freeze and crash repeatedly, and eventually it got stuck in a boot loop, where it has remained since.
The phone vibrates during boot attempts, and I can still access Recovery Mode and manually power it off. However, based on forum posts, the new update appears to have removed the option to wipe the cache partition, leaving only a factory reset, which I want to avoid because I still have data on my phone.
I also attempted to flash older firmware via Odin, but the update seems to have removed/disabled Download Mode, instead showing only instructions for a soft reset (Power + Volume Down).
I took the phone to uBreakiFix for data recovery, but they were unable to proceed due to the missing Download Mode.
I then shipped the device directly to Samsung, and they quoted me for a motherboard replacement. When I called for clarification, they said something along the lines of โsince the fingerprint sensor isnโt working, the board needs to be replaced,โ which doesnโt make much sense given that everything was working fine before the update, and the phone is still stuck in a boot loop. (I assume they were not able to get it powered on). It seems like the diagnosis was based mainly on my written description rather than a full evaluation.
At this point, Iโm unsure how to proceed. I was able to back up everything except my gallery before the phone fully entered the boot loop, and recovering that data is my main priority.
The phone still vibrates when charging, attempts to boot, and can enter recovery mode normally. Iโve also tried tapping/massaging and the freezer method (twice) with no success.
Is this likely related to a motherboard issue that others have mentioned? Could this be a failed/corrupted software update? Or possibly a battery-related issue causing instability?
The phone has been babied with a case and a screen protector from the moment of unboxing.
Iโd like to recover my data and keep the phone in the same condition it was in, but I also donโt want to throw money at guesses without knowing the root cause.
Which I assume means data recovery is out of the window. If the motherboard is indeed the issue, it's sad seeing $1k+ flagships becoming glorified paperweights, babied or not.
That's the issue, though, the phone was perfectly fine, whether it was using the fingerprint scanner to unlock or the battery life. I actually was eying on upgrading my phone, but since the new ones didn't appeal as much and the S23 Ultra was working fine, I backed out.
No slowdowns, issues, or anything of the sort until the update. Unless it was an unfortunate coincidence that I got hit with the motherboard issue right after the overnight update, it doesn't line up.
And correct me if I'm wrong, but if I did have the motherboard issue, wouldn't my phone give me trouble going into the recovery menu and the "download menu: that was now removed.
They are no hassle to get into, other than the issue that the new security update removed both the "Wipe Cache Partition" and the actual download menu if the phone isn't in "Maintenance Mode."
I've tried to use Smart Switch on PC when it was in the bootloop, and the "download menu", but my PC didn't recognize it. I downloaded the Samsung USB drivers as well to no avail.
I'll try again, this time in the recovery menu, and see if there's progress.
*Update* Smart Switch unfortunately doesn't recognize the device in recovery mode as well. Reinstalled drivers, and it didn't help.
The april update ruined the phone! Battery drops after little use, it takes 5+ hours to fully charge. It basically needs to be connected to a charger 24/7 now, in order to work. Samsung needs to fix the update ASAP!!!
