Cannot program STM32H750IBX, connection time out

[ktak]

Hello,

We're working on a custom board for the STM32H750IBX. Our boards arrived. The first time, the chip was installed poorly and shorted out. We assembled a new board at the SMT factory with the new chip, but we still can't connect to the chip to program it.

We checked the voltage and the connection as best we could. We couldn't check the chip itself because it's a BGA package. However, we did an X-ray, and everything looks fine.

We tried connecting with STMCUBE IDE and ST_LINK Utility, but they still can't recognize the target.

We've exhausted all possible solutions and are asking the community for help.

Schematics:STM32H750IB SCHEMATICS

Layout:

RED ARE SWD LINES

[TDK · Accepted solution]

> STM32H750IBX

This chip doesn't exist. STM32H750IBK maybe?

VDD (K4) is shorted to GND.

> ST_LINK Utility

This is not supported. Use STM32CubeProgrammer.

[ktak]

Thank you for your fast response!

I don't know how we(few people) didn't see the VDD pin connected to ground.

I downloaded the STM32CUBEPROGRAMMER and I successfully connected to the MCU once, even could to program it once and read the memory back.

But with CubeIDE I can't connect and program the MCU.

After I reset the board I can't connect again, even with STM32CUBEPROGRAMMER. 

As I understand the MCU can function partly with one VDD shorted to ground? Only some module will not be available, right?

[TDK]

> As I understand the MCU can function partly with one VDD shorted to ground? Only some module will not be available, right?

With one VDD pin shorted to ground, you are firmly outside of the operating conditions and behavior is not guaranteed in any way. It's not in a viable state, this is a fatal error. I'm surprised it connects at all.