STM32L4S5VIT6 would not run program with external power source

[Maxwell303]

I have a program that is about PWM. It runs fine when board's micro USB(CN7) is attached to my PC. But when I plug my external power supply to my micro USB, my program does not run at all. Instead, LD6 will start slowly blinking red light.

I tried to update ST-Link/V2-1 to V2J38M27. Supply voltage from VIN and GND pin. And switch jumper(JP4) across all five modes. But the problem still exist.

By the way, my source is 5v, 2A(I switch to 1A,but no avail) , board is B-L4S5I-IOT01A.

Has anybody faced this problem before? Thank you in advance!

Best regards

[Uwe Bonnes]

Is VDDIO present?

[Maxwell303]

I have checked voltage between JP5. It is about 2V. And it seems output voltage of pins still present. My motor still turning, but not following my program. Sorry I'm new to embedded system, so I don't really know how to measure VDDIO.