I just received STM32MP157F-EV1. On boot, the LCD displays nothing and the onboard ST-Link will not properly enumerate (Windows says "USB Device Not Recognized"). Latest ST-Link driver is installed and working with other kits. Is this a faulty board?

[DPade.1]

The ST-Link LEDs are very dimly lit when powered...they are much brighter on my STM32MP157F-DK2 board. I suspect some hardware problem with the MPU board. Also, the CPU LEDs do appear to be running (the Linux Blue LED blinks after a while, and with the SD Card removed the Red LED blinks as in DFU mode). Just not sure why there is no display (no backlight) and no ST-Link function.

[PatrickF]

Hi,

ST-Link is quite independant of the rest of the system, so your two issues are likely not linked.

1) For display issue,

please check potential misconnection of the display. Slightly press on the display on the opposite side of the screws.

See https://wiki.st.com/stm32mpu/wiki/Getting_started/STM32MP1_boards/STM32MP157x-EV1/Let%27s_start/Unpack_the_STM32MP157x-EV1_board

Do you have the three green leds on the display ?

As an aternative to the ST-Link VCP console, playing with JP4 and JP5, you could use old fashioned DB9 UART connector (UART4 on motherboard) to see if the board correctly boot or provide error message. But if you see blue led, this mean uBoot is correctly started, so I'm confident on that.

2) For ST-Link, please check JP1. It must not be present to have ST-Link to work.

If you does not connect USB, but just power up the board (with CN1), the ST-Link LED LD6 should blink slowly.

If you does not power up the board (i.e. no CN1), but connect ST-Link USB, the ST-Link LED LD6 should bright fixed once enumerated.

You might also check behavior using the MB1263C board alone (i.e. removed from the motherboard).

Regards.

[DPade.1]

Thanks for your response!

1) For display issue,

please check potential misconnection of the display. Slightly press on the display on the opposite side of the screws.

See https://wiki.st.com/stm32mpu/wiki/Getting_started/STM32MP1_boards/STM32MP157x-EV1/Let%27s_start/Unpack_the_STM32MP157x-EV1_board

Do you have the three green leds on the display ?

---> Yes, I have the 3 Green LEDs lit, and it does appear Linux is running, just no display on the LCD (I can tell the backlight is on, just a black screen).

2) For ST-Link, please check JP1. It must not be present to have ST-Link to work.

---> This was the issue. JP1 was closed by default. Opening JP1 let me connect to the ST-Link MCU. Unfortunately, my version of Keil doesn't support the ST-Link V2-1, so I ended up using an external debugger anyway.

I am up and running with what I need to do now, so thank you for your help! (I don't need the display for what I'm working on)

[PatrickF]

Nice to see you are able to play with the board.

1) it's a pity for the display, which might have been broke/disconnected during transport.

2) for ST-Link, even if you use an external debugger connected on Motherboard JTAG 20 pins socket, you could still use STLINK VCP for console (same than for DK2 and more handy than a specific DB9/USB cable).

Regards.

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