Linux on Prime not working

[Jean-Baptiste Boric]

I haven't tried this in a really long time, but I used to apply 3.3v onto the TP907 pad and press the reset button to trigger the SoC recovery mode.

Personally I'd try connecting the calculator to a Linux machine and look into the kernel logs for details, but that's because I don't know how to check for USB enumeration or kernel events on Windows. Maybe you've got a defective or charge-only USB cable?