STM32H757 Eval boards not working

[Jagan1]

HI

We have purchased few STM32H757 Eval board for initial evaluation. We received the boards

We have generated code using STM32CubeMX and added just GPIO configs.(PK3,PK4,PK5 as outputs) and flashed code. it was working. we disconnected powersupply and connected back from then led's not toggling and also any code not flashing.

and the output is No device found on the target. what may be the reason, how to overcome this. even tried in STM32CubeIDE still no luck.

STMicroelectronics ST-LINK GDB server. Version 7.11.0

Copyright (c) 2025, STMicroelectronics. All rights reserved.

Starting server with the following options:

Persistent Mode : Disabled

Logging Level : 1

Listen Port Number : 61234

Status Refresh Delay : 15s

Verbose Mode : Disabled

SWD Debug : Enabled

InitWhile : Enabled

Target no device found

Error in initializing ST-LINK device.

Reason: No device found on target.

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add-symbol-file "c:/Users/JNEKKALAPUDI/Documents/stm/test_gen/for_Final_test/CM7/build/for_Final_test_CM7.elf"

add symbol table from file "c:/Users/JNEKKALAPUDI/Documents/stm/test_gen/for_Final_test/CM7/build/for_Final_test_CM7.elf"

(y or n) [answered Y; input not from terminal]

Reading symbols from c:/Users/JNEKKALAPUDI/Documents/stm/test_gen/for_Final_test/CM7/build/for_Final_test_CM7.elf...

cube has exited with code 4

[mƎALLEm]

Hello,

What is the power supply config you set in CubeMx? SMPS or LDO.

If LDO you have locked the board and you need to recover it. See How can I recover my STM32H7/STM32H7RS board after facing a power configuration deadlock?

If it was configured in SMPS please attach you ioc file.