STM32F446 starting squence

fab04 · ‎2025-10-23

Hi everybody,

I've two cards with a STM32F446 on them.

My first one works very well, the µc starts a each time.

On the second card, the µc starts sometimes (I have a LED on my card that blinks at start).

I've checked Vcap (2.2µF), the 3V3 rising (1ms), boot is well connected to GND with a 10k resistor.

I cannot see what happens in debug mode, because in debug mode , it starts everytime.

Is there a mean to check something else ?

I don't understand what happens.

If you have some ideas...

Thank you.

mƎALLEm · ‎2025-10-23

Hello,

@fab04 wrote:

Hi everybody,

I've two cards with a STM32F446 on them.

Which board? custom board? ST board?

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TDK · ‎2025-10-23

Usually this is due to a hardware issue. Perhaps bad design, perhaps manufacturing defect such as a cold solder joint.

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