Restore Portenta to factory firmware

I have a Portenta H7 ABX00042 installed into the breakout board ASX00031.
I connected a USB C cable to the Portenta for power. The Portenta has a orange LED that is solid and blinks once every 15 seconds. Pressing the reset button - double tapping the reset and power off and on has no effect. I have connected an STLINK-V2 to the JTAG connector on the breakout board. I am unable to connect using the STM32CubeProgrammer - No STM32 target found!

I'm seeing the same behavior. In my case I wiped the entire processor because I'm planning to use the board with threadX. It now appears that the power supplies are not all coming up. My best guess is the chip comes up in some kind of low power mode and sets GPIOs or writes to I2C to bring the other supplies up. The 3.3V is not coming up so my STLink V3 throws the error No Target Found.

Your right about I2C controlling power. There is a fancy power management chip, MC34PF1550A4EP, that is setup with I2C to provide VCAP, 3V3, 3v1, 1v8, 1V2, and 1V0.

Good luck finding where all of this. This appears to be part of it.

Edit: the magic of the power on config is in the A4 of MC34PF1550A4EP. It is a pre-programmed profile.

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I am facing a similar problem with my Portenta and ST-LinkV3, i.e. no 3V3 voltage on the JTAG connector, so I am unable to debug because ST-Link refuses to connect, while 3V1 is generated OK by the PMIC.
Have you been able to overcome the issue?

Many thanks for your help


If this is still in time...

I've overcome this issue by directly connecting a 3v power supply to the 3v3 and gnd pins of the portenta so the core receives a voltage. From then on I was able to erase the chip flash and use arduino to flash a new bootloader.

Now I'm trying to get the i2c power management ic going to be able to use the portenta with the stm32cubeIDE.

Hi, rick!

just yesterday I had finally the debugger working, please check:


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