CPU can't work , UART don't send any message

We had develop a new carrier board . I use Jetson xavier cpu module on my carrier board and measure Power & Sequence (meet spec) . but when I connected uart ,I can’t see any message . try to boot recovery mode but it also fail. cpu seem to don’t work… What can I confirm in the hardware? Thanks

hello Kimichang,

may I know your connections for the serial console.
BTW, please refer to Jetson AGX Xavier Platform Adaptation and Bring-Up Guide for the documentation,

Thank you for your reply.
PC --> USB Cable --> carrier board [(FT4232HL)USB to UART D Port] --> nVIDIA CPU Module

Hi Jerry
I found the problem. Because the UART1(tx/rts) I am not give the HI-Z status. NOW it can booting!