How to recover glitching Galaxy S9?


Question

The bad


Last week I totaled a Galaxy S9's screen which I owned for over two years. I liked the phone so I headed up on Facebook market to look for another one.


I discovered a phone that I liked and went on to buy it.


When I had the phone in my hands, before paying, I run a service code (#0011# to see if all sensors/screen etc worked). This passed so I bought the phone.


Also, the phone won't do Samsung updates. It would either throw an error after download (The downloaded file is not correct) or restart when attempting.


The ugly


Here's the harsh part: not long after leaving the dodgy seller, while going home, the phone started behaving really weirdly: sudden restarts, some screen glitches, and artifacts. The phone also loses battery pretty quickly, either due to the weird sudden restarts or else.
Screenshot, Homescreen with purple streaks


Note the purple glitches. I was able to record these with a screenshot, meaning it comes from the GPU chip?


The good


The first thing I looked at was the water damage sticker beneath the sim tray:
Water damage sticker


I then managed to charge the phone fully and log in with a Google account, which allowed me to do further diagnostics. I installed Geekbench and run a test. The phone has a normal score for this model.


I tried filming, calling, playing games on the phone and all seems well.


The only times when the phone restarts are after receiving an error like "Google Services App crashed" or "Samsung Services App crashed" or suddenly when I try to use a service or disable/uninstall blootware.


I also managed to get the phone to update through Samsung Smart Switch to the latest update (Security Patch 1 Dec 2020)


Resolution:


I have a few options for repairing this weird phone



  1. Find what version of firmware I could flash on the phone and hope for a stock experience (including bootloader etc) - This option assumes that the hardware is intact, the chipset has no water damage, etc.



  2. Open the, in which case I lose IP68 (assuming this is not lost already) and change the motherboard with my old phone's.




How to proceed from here?


I am a bit unfamiliar with choosing the right firmware etc. I have the following information in the phone's software info:



  • One U.I 2.1



  • Android 10



  • Baseband version: G960FXXSBETG8



  • Kernel version: 4.9.118-18847185 # 1 Mon Aug KST 2020



  • Build number QP1A.190711.020.G960FXXSBETH1



  • Knox 3.4.1 API level 30 TIMA 4.0.0



  • Service provider SW ver.: SAOMC_SM-G960F_CKH_DRE_QQ_0009 / 2b282a7f23017ece (DRE/DRE/DRE)



  • CSC: G960FCKHCFTK1



  • AP: G960FXXSCFTK2



  • CP: G960FXXUCFTJ1




I tried downloading this firmware version, but from what I've read the bootloader version here is too old and cannot replace the current bootloader. How can I determine the bootloader version on my phone? XDA forums say it's the 5th digit from the Build Number. However, my Build Number doesn't seem to respect the format of the above file.


Can anyone suggest what to do next? I'm itching to open the phone, but I think it's wiser to try and repair it from firmware.


Answer

Thank you alecxs for your support. It kept restarting and showing a bicolour (green/blue) padlock which I assumed was a security feature from the carrier. The phone will work for extended periods of time, however, it would randomly restart when using standard google/samsung services, even with a new firmware.


Topics


2D Engines   3D Engines   9-Patch   Action Bars   Activities   ADB   Advertisements   Analytics   Animations   ANR   AOP   API   APK   APT   Architecture   Audio   Autocomplete   Background Processing   Backward Compatibility   Badges   Bar Codes   Benchmarking   Bitmaps   Bluetooth   Blur Effects   Bread Crumbs   BRMS   Browser Extensions   Build Systems   Bundles   Buttons   Caching   Camera   Canvas   Cards   Carousels   Changelog   Checkboxes   Cloud Storages   Color Analysis   Color Pickers   Colors   Comet/Push   Compass Sensors   Conferences   Content Providers   Continuous Integration   Crash Reports   Credit Cards   Credits   CSV   Curl/Flip   Data Binding   Data Generators   Data Structures   Database   Database Browsers   Date &   Debugging   Decompilers   Deep Links   Dependency Injections   Design   Design Patterns   Dex   Dialogs   Distributed Computing   Distribution Platforms   Download Managers   Drawables   Emoji   Emulators   EPUB   Equalizers &   Event Buses   Exception Handling   Face Recognition   Feedback &   File System   File/Directory   Fingerprint   Floating Action   Fonts   Forms   Fragments   FRP   FSM   Functional Programming   Gamepads   Games   Geocaching   Gestures   GIF   Glow Pad   Gradle Plugins   Graphics   Grid Views   Highlighting   HTML   HTTP Mocking   Icons   IDE   IDE Plugins   Image Croppers   Image Loaders   Image Pickers   Image Processing   Image Views   Instrumentation   Intents   Job Schedulers   JSON   Keyboard   Kotlin   Layouts   Library Demos   List View   List Views   Localization   Location   Lock Patterns   Logcat   Logging   Mails   Maps   Markdown   Mathematics   Maven Plugins   MBaaS   Media   Menus   Messaging   MIME   Mobile Web   Native Image   Navigation   NDK   Networking   NFC   NoSQL   Number Pickers   OAuth   Object Mocking   OCR Engines   OpenGL   ORM   Other Pickers   Parallax List   Parcelables   Particle Systems   Password Inputs   PDF   Permissions   Physics Engines   Platforms   Plugin Frameworks   Preferences   Progress Indicators   ProGuard   Properties   Protocol Buffer   Pull To   Purchases   Push/Pull   QR Codes   Quick Return   Radio Buttons   Range Bars   Ratings   Recycler Views   Resources   REST   Ripple Effects   RSS   Screenshots   Scripting   Scroll Views   SDK   Search Inputs   Security   Sensors   Services   Showcase Views   Signatures   Sliding Panels   Snackbars   SOAP   Social Networks   Spannable   Spinners   Splash Screens   SSH   Static Analysis   Status Bars   Styling   SVG   System   Tags   Task Managers   TDD &   Template Engines   Testing   Testing Tools   Text Formatting   Text Views   Text Watchers   Text-to   Toasts   Toolkits For   Tools   Tooltips   Trainings   TV   Twitter   Updaters   USB   User Stories   Utils   Validation   Video   View Adapters   View Pagers   Views   Watch Face   Wearable Data   Wearables   Weather   Web Tools   Web Views   WebRTC   WebSockets   Wheel Widgets   Wi-Fi   Widgets   Windows   Wizards   XML   XMPP   YAML   ZIP Codes