STM32F4DISCOVERY issue - RDP stuck at 0xFF

[raniaa]

Hey everyone,

I'm having a weird issue with my STM32F4DISCOVERY board (MB997). It was working fine before, but now I can't program it anymore.

Board info:

• Board: STM32F4DISCOVERY

• Device: STM32F407VGT6

• ST-LINK FW: V2J46M33

• ST-LINK SN: 0671FF37324D423143244649

Symptoms:

• STM32CubeProgrammer connects OK (Device ID 0x413 confirmed)

• Flash erase fails: Error: failed to erase memory sectors [0-2]

• RDP Option Byte shows 0xFF (corrupted)

• BOR_LEV = 3 (BOR OFF)

• Writing RDP from 0xFF to 0xAA fails, always comes back as 0xFF

• VDD measured at 2.89V

What I've tried:

• Under Reset mode

• ST-LINK Utility

• STM32cubeProgrammer

• Different USB cable

• ST-LINK firmware update

Nothing works. RDP is stuck at 0xFF.

Has anyone seen this before? Any suggestions?

Thanks in advance!

[mƎALLEm]

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@raniaa wrote:

 i've used a power stage (l298n motor driver )

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OK that depends on how you've connected that power stage to the board .. I'm afraid you've may broken the board while connecting that device to the Disco board while manipulating high level voltages of the motor.

Do you have another board to test? if yes, upload the same program to that board without connecting the motor and its power stage, if it keeps working, unfortunately, I suspect you've broken the first board..

[raniaa]

If the same program works on the second board, can I conclude that the first board is faulty? And if the same problem also appears on the second board, what should I check or do next?

[mƎALLEm]

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@raniaa wrote:

If the same program works on the second board, can I conclude that the first board is faulty? And if the same problem also appears on the second board, what should I check or do next?

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If with the second board and without connecting something else still working, the first board is broken.

If with the second board and without connecting something else, stops working, there is something in your application/code causes the behavior..