STM32F407VET6 ICB JLINK : No device found

[Johi]

Hello,

I have 3 of these (chinese origin) boards, 2 are failing communication, 1 is ok.

In essence my STLINK-V3SET fails to connect to the board but the led's on the brand new board are blinking. Therefore the MCU processor is running. I measured the 3.3V power supply pins on my STLINK and they are not powering the board (board is powered externally), so a 3.3 conflict does not seem to be the origin of the broken board, my question: are there any other steps that can be taken to repair the JLINK interface or at least find the origin of the problem? 

[Mike_ST]

Hello,

we don't know this board, do you have the schematic ?

You're talking about JLINK and ST-LINK. Which one are you using ?

Maybe the board that is not working already has a firmware inside that when executing prevents to use the debug pins.

Solution would be to connect under reset or connect via bootloader with boot0 set to 1 and perform a mass erase.

[Johi]

Hello,

Schematic drawing see attachement.

As I see jlink with both SWD and JTAG capabilities via ST-LINK V3.

Both work correctly on twin board that is OK.

Tried the following:

Where pin 3 and 2 are connected on pin 8.

So I suppose all is ok.

What I do see is that the 3.3V on the bogus board is there but the ac voltage on the Y1 is much lower compared to the OK board. (140 mV ok & 14 mV nok). However one of the LED's on the board is blinking so the processor is running. I also replaced Y1 with a brand new one. However I do not believe Y1 is necessary for an operational board.

So thank you for the reply but no result yet.

[Tesla DeLorean]

Looks more like a Generic ARM 20-pin JTAG, not "J-LINK" specifically, although the Silk-Screen suggests that what they referred to it as

You could select "SWD" as the connection method, it uses a sub-set of the full JTAG pins.

ST Tools may reject connectivity if the parts is a counterfeit or clone device. Board and processor need to be properly powered for the SWD/JTAG interface to be viable.

[Johi]

Thank you for the info.

I have 3 boards, identical design (except for the color of the headers :).

The first board, the older one, SWD and JTAG operating fully no connection problems whatsoever.

The 2 recent boards, SWD, JTAG, even connect under reset with Boot 0 = 1, no connection.

Therefore, sorry to say and respect for what you do for the people on the forum, but your post did not hit the target this time. 

[Johi]

I connected my scope to the board and this gave me the following image: (SWD connection, red is clock)

Do you have any idea what kind of protocol I need to select or any other insights that could lead to the solution i.e. my ST-LINK programmer finding the target board?

Is there a way to find out if the MCU is counterfeit? The imprint seems genuine.