Wireless Stick Lite flashing issue

I have several Wireless Stick Lites and up to now there have been no problems to flash them using Arduino IDE. Only one brand new board is not working. I am trying to flash a simple program blinking the onboard led and writing some text on serial monitor. Flashing seems to be ok:

Compressed 3072 bytes to 128…

Writing at 0x00008000… (100 %)
Wrote 3072 bytes (128 compressed) at 0x00008000 in 0.0 seconds (effective 819.2 kbit/s)…
Hash of data verified.

I can also read the calibration data so there is no problem with communication:
espefuse.py -p COM21 adc_info
espefuse.py v2.9-dev
Connecting…
ADC VRef calibration: None (1100mV nominal)

But when I open the serial monitor and press the RST button I get the following message:
18:31:28.473 -> ets Jun 8 2016 00:22:57
18:31:28.473 ->
18:31:28.473 -> rst:0x1 (POWERON_RESET),boot:0x3 (DOWNLOAD_BOOT(UART0/UART1/SDIO_REI_REO_V2))
18:31:28.473 -> waiting for download

Program is not running because the led is not blinking. Flashing and running the same program with another Wireless Stick Lite borad is no problem. What is wrong with this board and how do I proceed to get my board alive again?

I managed to find the root cause for this problem: GPIO0 is constantly grounded even though it should be pulled down only if PRG button is pressed. This is the reason why ESP32 will never enter into normal execution mode but flashing is working. Next step is to try to get a new board from the seller, I hope I will succeed because my board is already soldered on the larger PCB…


You can see if there is such a resistor on the board. If so, you need to tilt the case a little to avoid it from touching the resistor.

There was no resistor on my PCB but it looks like there is a quality issue with the installation of the RF shield. I removed the shield completely and the module started to work. I suppose that there was a short circuit between the shield and the inner solder pad near the shield. I wonder if this will cause more problems in future while I am using the module in a quite vibrating environment…