STM32F103C8T6 Sometimes it's good and sometimes it's bad

[leo12345678]

After normal power-on, the MCU does not run, but as long as something is used to shield it, it will return to normal. Help to see what is the reaso

[STOne-32]

Hi @leo12345678 ,

Try to remove R13, pull-up resistor on reset pin, it is not required. we have one internally.

Hope it helps.

STOne-32.

[leo12345678]

We remove the R13  and it still didn't work, but we blew it with a fan for a while and it came back to normal, so what's going on here? Thank you very much!

[Andrew Neil]

crystal oscillator not starting?

is this board your own design, or purchased from some supplier?

if the latter, is it your own firmware? Do you have any known-good reference firmware?