Bricked, with blue dotty wallpaper, what next?

Hi, I have inherited a somewhat bricked machine, looks new, told the kid did one demo print.
Turning on, get 2 pairs of relay clicks, no beeps. Display has blue wallpaper with wavy dots.
I was able to flash firmware to the display, but when booted without micro-SD it stays the same. Instructions said to use FAT format, but that gave error telling me to use FAT32, which I did, and it “successed”.
So try to flash mainboard. It shows no response to SD cards. Display still wallpaper, no text. No beeps, no motor movement.

So what can I do next? Is this consistent with a failed mainboard? Replacement boards are like us$30 on Aliexpress.

I`m having the exact same problem on a printer I purchased just last month (Ender 3 V3 SE). On my printer, I have the red light for the CR-Touch sensor continuously lit. It was working normally until yesterday.

Flashing the firmware on the screen works, trying to flash motherboard firmware doesn’t seem to work (stuck on blue screen for ever).

Does your printer also have the CR touch continuiously shining in red?
Did you manage to fix this problem?

Hi i am on a mac so cannot format the SD card as per the Creality instructions so i ended up using a brand new card and the firmware update finally worked ( i renamed the machine firmware to v6.bin)