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!

[raniaa]

I have tried using DFU mode, but the card is not detected at all. I connected BOOT0 to VDD and even tried connecting PB2 (BOOT1) to GND. Despite performing a hardware reset, the device does not appear in the Device Manager or in Zadig. 

[MM..1]

DFU isnt only USB (AN2606 actualy on page 162) for this you require usb to uart and connect RX TX GND to right pins ...

[raniaa]

Hello! I'm using a PL2303, but I'm getting an error even though I connected BOOT0 to VDD.

[MM..1]

You lack more info, where you connect RX TX and how you reset board with BOOT0 High. Your issue is curious, if you realy connect STLINK and read ID of chip, but nothink more... Plus how you setup PL2303 to 3V3 mode...

[mƎALLEm]

Hello @raniaa ,

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@raniaa wrote:

I'm using a PL2303, but I'm getting an error even though I connected BOOT0 to VDD.

---

We start to deviate here from the original subject. Introducing PL2303 could introduce more complexity in your case. 

1- What you did to the board before it starts to not able to connect?

2- Are you sharing the board with other people? if yes that's indeed an issue and need from you ton contact these people to ask them what they modify on the board: unsolder solder bridge, remove some components from the board etc .. we don't have a full picture..

3- What about the following jumpers? are they fitted?

[raniaa]

1-I tested my code with the GJA25, and it worked the first time. However, the second time, a launch error appeared.

2-No, it is a new board. I only tested it twice, and I did not share it with anyone.

3-Yes, the jumpers are present and correctly fitted

[mƎALLEm]

---

@raniaa wrote:

1-I tested my code with the GJA25,

---

What do you mean by "GJA25"?

[raniaa]

a motor encoder

[mƎALLEm]

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@raniaa wrote:

a motor encoder

---

That's indeed a missing information you would provide from the beginning.

Do you mean this motor?:

If yes how did you connect it?

How did you connect the motor itself (I'm not talking about the encoder) but about the motor itself? directly or over a power stage dedicated to interface a such kind of motors?

[raniaa]

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