Switch Lite charging - black screen, no touch and sound

I do have a defect switch lite and I am at a loss.
Switch is not booting, but charging seems ok. After starting ampmeter starts with 0.41a and jumps to 1.12a which seems to be fine.

I cannot see any reaction on the screen. Backlight seems not to work. Touchscreen / sound is also not working.

I have checked for shorts round me M92 and BQ but could not find any problems.

My first thought was maybe a bad ribbon cable for the display - but in this case backlight / sound should work if I am right.

As I am running out of ideas - any ideas / experiences what could cause such a behavior

Did you ever resolve this? I too have the same problem.

Well - I sold it - probably too early - as a good guess I think it was a faulty backlight IC.