can't start the BBB card when the UART0 is plugged

Hello everybody,

I have a problem with the UART0 ,so the BBB card doesn’t start when the UART0 is plugged.
I did a small circuit to go from full-duplex to half-duplex on that serial port, I did the same on the UART1 and works without any problem.
any suggestions ?

Thanks for your help

Your probably stuck in u-boot..

What version do you have installed?

The current shipping version requires a "space key" input (0x20) to
break into u-boot shell..