We have a custom TX2 carrier board, most of the units are working fine but we have one unit that seems to have issues with power up. I probed around and noticed that UART2_RX and UART2_TX for pin B16 and B15 are 0V. On the working unit I see 1.8V for both pins. I was wondering where is this 1.8V coming from? We supply the module with 12V. Does the 1.8V then come from the module it self? The 1.8V for the carrier board looks fine. I checked the power up sequence and see the button signal, VIN_PWR_BAD and CARRIER_PWR_ON are all correct. How do I check to see if the module is correctly powered? I swapped TX2 modules and the problematic board still does not power up which leads me to think it is the carrier board. One of the signals must not be getting to the TX2 module to boot it. Any help would be much appreciated. Thank you.
Also noticed there is 0V on UART2_RTS# and UART2_CTS#, A15 and A16 respectively.
Hi, did you compare the pin status during power on between failure board and good board? Also please check the strapping pins status as said in OEM DG.
Did you probe all signals related to power on sequence as listed in OEM DG? Is it in recovery mode when power on with failure board?