STM board not recognized

[samsam0510]

Hi, I'm currently using Nucleo-U575ZI-Q.

I've done nothing to it except leaving it for a day and just plugged it to my laptop again but it doesn't recognize my board now.

When I connect it with my laptop, fail.txt shows up with a message "The interface firmware FAILED to reset/halt the target MCU"

I figured out that the voltage supplied by the USB is 0.7V which is way lower than the operating voltage.

How can I fix this?

 

I'll add a photo that shows how it looks after I hook up with my laptop.

Also this is the error message from STM32CubeProgrammer(I tried to reset the firmware):

22:50:39 : STM32CubeProgrammer API v2.17.0 | Windows-64Bits
22:50:47 : UR connection mode is defined with the HWrst reset mode
22:50:47 : ST-LINK SN : 002400203431511537393330
22:50:47 : ST-LINK FW : V3J15M7
22:50:47 : Board : NUCLEO-U575ZI-Q
22:50:47 : Voltage : 0.70V
22:50:47 : Error: No STM32 target found! If your product embeds Debug Authentication, please perform a discovery using Debug Authentication

[TDK]

> Voltage : 0.70V

This is not enough voltage for the chip to run. Looks like your jumper settings are correct.

The board is probably damaged. You can look at the schematic to try and figure out what is damaged and replace it.

https://www.st.com/resource/en/schematic_pack/mb1549-u575ziq-c05-schematic.pdf

 

[samsam0510]

Thanks to TDK, this is how I got so far.

Based on the schematic, I tracked how the power was supplied to the board and discovered that 1.0~1.1V was coming out from 5V, by testing pin TP3.

Since 5V_STLK and 5V are connected by default, the 5V_STLK was also approx 1.1V.

So, I removed the connector that connects 5V_STLK and 5V and checked again, figuring out that 5V_STLK worked properly as 5V.

Therefore, I'm supposing there's some short circuit connected with 5V.

I think this LDO has a problem because when I plug the USB C cable and switch the power selection pin header from 5V_STLK to 5V_USB_C, it suddenly heats up very high.

I get a decent 4.7V output from 5V but a 0.5V output from the 3V3 node.

 

I'll try some more and share the results.
Thanks:)

[TDK]

It could be U10 that's the issue, but it could also be something downstream of that on the 3V3 line. If something downstream is shorted, then U10 heating up is expected.