Capturing logs of embedded linux behind progress bar from my machine

I have embedded linux that stops while it is completing to 100% . On monitor I am seeing progress bar that goes till 48% and stopped without completion.

I want to capture what is happening on this. But there is no tty mode.

So I want to connect usb from serial port of my device to my debian machine and capture the logs and see what is happening behind proguress bar and real errors.

One of my friends told me you can use screen command to capture from /dev/tty on you debian machine connected to embedded linx. But I don't know how it is possible...

Could you help me?