STM32F446 custom, will not boot without debugger

[FJB2069]

Custom board will not run without debugger.  With debugger removed and cycling power I have manually touch NRST to ground to get it to run.

The NRST is only connected to SWD pin, but when debugger is removed it is not connected.  Theis is no ST-LINK on the board.  The NRST does measure 3.3 volts after power up.

I do use BOOT0 pin as an output.  It is configured low with pull down in .IOC  (could this be issue?)

Debugger is set to hardware reset, but I have tried all resets.

Debugger is set to break at main (not sure if it is trying to break at main without debugger attached?)  I tried to not break at main and will not run with or without debugger.

I also put HAL_DELAY(3000); after Hal_init(),  no difference.

Here is how my clocks are set:

Any suggestions on why it will not run?

[Andrew Neil]

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@FJB2069 wrote:

Custom board will not run without debugger. 

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Then you'll need to post the schematic

[FJB2069]

[Tesla DeLorean]

BOOT0 with a local 10K pull-down looks Ok. What do you mean use as Output?

With a single VCAP I think expectations is for 4.7uF, not 2.2uF

[TDK]

Why is C8 here?

VSS should be connected directly to ground.

Otherwise seems okay-ish. Should have 0.1 uF decoupling cap on each VDD pin. Unlikely to prevent it from booting.

Voltage at PB0 may be a problem. If using the ADC, voltages above VDDA are not allowed. Included schematic is missing details.

[FJB2069 · Accepted solution]

I found issue.  Pull down resistor on Boot0 had a poor solder joint!

Thanks for all your help!