I have a boot looping Samsung Galaxy S4 Mini LTE (also known as GT-i9195 or
serranoltexx – this is not GT-i9195i or
Current behavior: when the phone is off, pressing power button results to normal boot screen with usual yellow text in the top left corner about custom kernel ("Set Warranty Bit : kernel"). The screen stays in this view for around 20 seconds, turns to black, vibration motor runs for two short periods and the system reboots. I guess the system is failing to boot until hardware watchdog resets the system due timeout exeeding. If I boot with Volume down + Home + Power held, the phone enters into download mode as usual. And if I boot with Volume up + Home + Power held, the phone enters recovery mode (TWRP version 18.104.22.168) where everything seems to work as usual, too. I was running LineageOS 16 (Android 9.0) with SELinux enforcement enabled with June 2019 security patches. The system has
XXUCOL3 modem firmware if I remember correctly.
In the end, I can successfully boot into download mode and into TWRP recovery. However, the system started to fail to boot to normal system after normal shutdown-restart cycle and the system was working okay before shutdown. Is there any way to diagnose and possibly fix the problem without wiping all the data?
Steps that I've already tried:
- Wiping Art/Dalwik Cache, Cache partition and System partition and re-installing full system image via TWRP.
- Removing battery
- Booting with SIM card and sdcard removed
I really want to understand why this happened to avoid it in the future. I really don't want to have a device that randomly enters this state and the only way to fix it is to wipe the whole device. Being able to bring the current system to usable state without full wipe would be a nice bonus because it avoids reconfiguring all the settings and apps again.
And yes, I know this device is old and I had to previously replace motherboard due emmc chip failing but I really like the form factor and no vendor is nowadays providing similar device. If Sharp Aquos R2 compact didn't have notches on the screen it would be my next phone.