It should be LM1117 to power him, STM32 is not so fragile, try the 1117 chip hot after power. Because STM32 is sometimes bad and easy to have a power pin directly short circuit, in addition, can you download it successfully and run it directly? No, look at the components on the IO such as LED, first determine whether the IO is running, and then check the LCD part. Like if the pull-up resistor was disconnected or something.
Also look at your BOOT Settings don't go wrong.