Why my MCU is not detected

[remi2]

In the picture:

pin 1 top left: VDD 3.3V

4 100n to GRND

14 to GRND

15 to VDD

16 to GRND

on their left 1µ and 10n F decoupling VDDA VSSA

pin 32 top right : VSS 0V GRND

pin 31 10K ohm to GRND

24 SWD clk

23 SWD dio

17 to GRND

top left and bottom right 100nF decoup. PWRS + the blue one 4.7µF

tried many combinations: with the reset on/off , boot0 on/off, swapped 23/34 ,

the ideMXcube and the standalone programmer wont see the MCU:

target not found,

ps: the red LED in ON .

my stlink v2 works in this setup with: another nucleo G4 and the generic "blue pill" fine.

Any help or suggestions ?

Thank you in advance.

[Tesla DeLorean]

Lack of any markings, are you sure this is a functional part.

[remi2]

I have just got three of these from farnell, the soldered one got too much flux ... 🙂

photo attached.

[remi2]

FYI, to solder the SMD, I used glue to hold the chip in place.

I didnt use wood glue, especially not superglue,

but paper glue, like we use in class rooms.

So my thought is that this glue has a resistance, maybe pins are shortcut-ted underneath,

I have just mesured the resistance of the glue, it is about 0.3 Mohm -> 300Kohm .

And yet the LED lights up .

I will retest after a while (more dried glue)

And then will try to clean up underneath the chip ...

Regards

[remi2]

Made another board, this time, no glue and no overheat, I soldered so quickly , I held the chip with my finger and didn't get burned ...

my question, BTW:

Am I missing the quartz ? because I taught, this chip can start with its own RC clock ...

Also, I am powering up the board with stlink2 's 3.3v , yes the stlink is a clone ...

Regards

[Tesla DeLorean]

The STM32 typically start from HSI or MSI, you have to manually start the HSE external one.

The secondary signs-of-life is sending the 0x7F data pattern via UART into the system loader. See AN2606, and AN3155

[AScha.3]

>this chip can start with its own RC clock.

right so.

you should see the clock tree in Cube or STM32cubeIDE ...right?