Samsung Galaxy A9 (2018) – Shuts down during boot/doesnt turn on

Hi everyone,

I could use some advice on an issue with my Samsung Galaxy A9 (2018).

Yesterday, some organic debris got into the USB-C cable connector and the phone's charging port, preventing it from charging. I cleaned both the cable and the port using isopropanol. After that, the phone charged properly again and worked normally for about half a day.

Current symptoms:

• The phone suddenly powered off and does not respond to the regular power button at all anymore.
• Using a key combination (Power + Volume Down), I managed to force-start it ONCE. It fully booted into the OS, showed around 94% battery, but crashed completely after about 1 minute. All other boot attempts failed during startup, crashing at different points during the boot animation.
• Download Mode ("Custom OS...") can still be accessed and remains stable most of the time.
• I cannot get into Recovery Mode (the phone does not respond to Power + Volume Up + Bixby).
• When connected to a charger, there is no charging indicator/animation on the screen.

My main goal is to get it to boot up just one last time to pull a backup before replacing it.

Thanks in advance for any help or insights!