I've just assembled a PCB with a ESP32-S3 on it. It has the buttons for reset and boot, but when connected by UART it gives the following output in a loop when reading serial.
invalid header: 0xffffffff ESP-ROM:esp32s3-20210327 Build:Mar 27 2021 rst:0x10 (RTCWDT_RTC_RST),boot:0x9 (SPI_FAST_FLASH_BOOT) invalid header: 0xffffffff invalid header: 0xffffffff It does not let me upload code, neither by using Espressif IDE nor Arduino IDE (even when pressing the reset or boot button).
My guess is that maybe the chip got damaged when using the hotplate while soldering the chip to the PCB. I connected the "boot" button into the GPIO0 pin with a pullup configuration, as well as the EN pin (reset).

